The Most Wildly Inconsistent Player on Each MLB Team

Every MLB team has steady producers they can count on for consistent production, as well as players who are incredibly streaky.

The inconsistency of a streaky player can bring about constant frustration from the team's fanbase and front office alike, as they are capable of carrying a team one week and producing absolutely nothing the next.

So here is a look at the most wildly inconsistent player on each MLB team, the player who has the upside to produce at a star-caliber level but fails to do so on a day-to-day basis.

Arizona Diamondbacks: SP Brandon McCarthy

Career Stats

37-41, 4.10 ERA, 106 ERA+, 456 K, 670 IP

Career History

Once a highly regarded pitching prospect in the White Sox organization, Brandon McCarthy failed to live up to his tremendous potential prior to joining the A's in 2011.

In two seasons in Oakland, he went a combined 17-15 with a 3.29 ERA as he was one of the best pitchers in the game when he was on the field. However, injuries limited him to just 43 starts over that span and have been an issue throughout his career.

Now a member of the Diamondbacks, he's 0-2 with a 7.47 ERA in his first three starts in the desert and continues to show top-flight potential, but lacks consistency.

Atlanta Braves: 2B Dan Uggla

Career Stats

.252/.343/.468, 212 HR, 629 RBI, 683 R

Career History

Dan Uggla has some of the best power of any second baseman in the history of the game, and he had 209 home runs in just seven big league seasons entering 2013.

However, he also strikes out a ton and has hit under .240 each of the past two seasons, as he is far from a consistent producer at the plate.

He's capable of going on a tear at the plate and carrying the offense for weeks at a time, but he also goes ice-cold for long periods as well.

Baltimore Orioles: SP Jake Arrieta

Career Stats

20-23, 5.33 ERA, 79 ERA+, 268 K, 349.1 IP

Career History

One of a number of high-upside starting pitchers the Orioles have developed of late, Arrieta went 10-8 with a 5.05 ERA for a bad Orioles team in 2011—and that was enough for him to earn the Opening Day start last season.

He threw seven innings of two-hit, shutout ball to open the season, and he was 2-2 with a 3.52 ERA through his first six starts of the year. However, he went 1-7 with a 7.71 ERA over his next 12 starts and found himself demoted to Triple-A in early July.

At 27, there is still time for him to figure it out, but the clock is ticking on him living up to his potential. He's in the Orioles rotation again this year and has been decent in two of his three starts, so maybe this is the year.

Boston Red Sox: 1B Mike Napoli

Career Stats

.258/.354/.506, 148 HR, 396 RBI, 377 R

Career History

The rest of the offensive game has not always been there, but Mike Napoli has always had some of the best power in the game as he's averaged 15.7 AB/HR in his career.

He was one of the most dynamic hitters in the game in 2011 when he hit .320 with 30 home runs in just 369 at-bats for the Rangers.

Early on last season was a perfect example of how streaky he can be, as he hit .435 with six home runs and 11 RBI over on five-game span in April, then hit .171 with one home run and two RBI over his next 11 games.

Chicago Cubs: RP Carlos Marmol

Career Stats

460 G, 22-29, 116-of-142 SV, 3.42 ERA, 128 ERA+, 678 K, 521.1 IP

Career History

Early on in his career, Carlos Marmol was one of the best relievers in all of baseball with a 2.54 ERA and 441 strikeouts in 308.1 innings of work and converting 61 of his 73 save chances.

However, he's always struggled with his control at 6.0 BB/9 for his career, and that has come back to bite him time and again.

He's lost the closer's role a number of times over the past three seasons, most recently within the first week of the 2013 season after recording a loss and blowing a save, and now he finds himself in the final year of his contract with his future as a whole in question.

Chicago White Sox: LF Dayan Viciedo

Career Stats

.260/.302/.435, 33 HR, 102 RBI, 95 R

Career History

Having signed Cuban defector Dayan Viciedo when he was 19,  the White Sox gave Viciedo a four-year, $10 million contract with high expectations for his future.

After back-to-back solid seasons in Triple-A, he stepped into an everyday role in the majors last season following the trade of Carlos Quentin.

The best example of his inconsistency was when he had a .351 BA, 8 HR, 24 RBI line in May, then followed it up with a .179 BA, 3 HR, 9 RBI line in June.

He's still only 24, and the potential is there for him to be a consistent power threat, but for now he remains a streaky power source at the dish.

Cincinnati Reds: SP Homer Bailey

Career Stats

39-34, 4.47 ERA, 93 ERA+, 524 K, 663 IP

Career History

Selected with the No. 7 pick in the 2004 draft, Bailey entered last season 25-23 with a 4.89 ERA in 78 career starts over the first five years of his career.

He finally tapped into his vast potential last year, going 13-10 with a 3.68 ERA as part of a terrific Reds rotation, and at 26 years old he's definitely a pitcher on the rise.

Last season, he recorded 21 quality starts in his 33 appearances, which is a good total. However, in his 12 non-quality starts he had an 8.07 ERA; when he was bad he was really bad.

Cleveland Indians: SP Justin Masterson

Career Stats

42-54, 4.09 ERA, 100 ERA+, 669 K, 847 IP

Career History

Used primarily as a reliever during his two seasons with the Red Sox, Masterson was shipped to Cleveland in the deal that brought Victor Martinez to Boston.

In 2011, he went 12-10 with a 3.21 ERA as he appeared to take a step forward toward being a frontline starter. He followed that up by going 11-15 with a 4.93 ERA last season, but that was still enough for him to be the Indians' Opening Day starter this year.

In his first three starts this season, he went 3-0 with a 0.41 ERA, but he was hit hard last time out as he allowed 11 hits and four earned runs in five innings of work. Time will tell if that was a blip on the radar, or him reverting back to his inconsistent self.

Colorado Rockies: RP Wilton Lopez

Career Stats

220 G, 13-13, 11-for-24 SV, 3.29 ERA, 173 K, 230 IP

Career History

The Rockies acquired Lopez from the Astros this offseason after converting 10 of 13 save chances with a 2.17 ERA last season out of the Houston 'pen.

The 29-year-old was expected to shore up the Rockies bullpen and perhaps serve as the heir to Rafael Betancourt in the ninth inning, but he has struggled mightily in the early going.

He's never had overpowering stuff (6.8 K/9 career), and he has an 8.53 ERA in seven appearances this season. That's largely the result of two rough outings, though, in which he allowed a combined five runs in two innings of work. He's been a solid setup option aside from that.

Detroit Tigers: C Alex Avila

Career Stats

.258/.354/.427, 42 HR, 177 RBI, 147 R

Career History

After Avila hit .228 over 294 at-bats in 2010, the Tigers had their concerns about turning over everyday catcher duties to him in 2011. 

However, he surprised everyone by hitting .295/.389/.506 with 19 home runs and 82 RBI, as he finished 12th in AL MVP voting.

He regressed last season, hitting .243 average with nine home runs and 48 RBI, and his production was up-and-down all season. His monthly averages were .220, .278, 188, .239, .268 and .220, and he had just one home run and eight RBI in June and July combined.

Houston Astros: SP Bud Norris

Career Stats

30-39, 4.43 ERA, 89 ERA+, 567 K, 582.2 IP

Career History

In four big league seasons, Bud Norris has shown flashes of being a positive arm for the Astros, and he's consistently posted a plus strikeout rate at 8.8 K/9.

His best season statistically came in 2011, when he went 6-11 with a 3.77 ERA, but he took a step forward last season as a whole.

In 29 starts last year, he made 17 quality starts in which he posted a 2.11 ERA. However, in his 12 non-quality starts he had a 9.83 ERA, and he failed to make it to the fourth inning three different times. The stuff is there, and he could be a sought-after trade chip come July, but he remains frustratingly inconsistent.

Kansas City Royals: RF Jeff Francoeur

Career Stats

.266/.309/.425, 138 HR, 605 RBI, 542 R

Career History

Jeff Francoeur burst onto the scene in 2005, hitting .300 with 14 home runs and 45 RBI over 70 games with the Braves after the team took him in the first round in 2002.

After back-to-back 100-RBI seasons in Atlanta following that, his average plummeted to .239. He was traded to the Mets, and after a poor 2010 he signed a one-year, $2.5 million deal with the Royals.

He rewarded them with a bounce-back 2011, hitting .285 with 20 home runs and 22 steals, and the team signed him to a two-year extension. He was bad again last year, and now at 29 he's looking for another bounce-back year.

Los Angeles Angels: DH Mark Trumbo

Career Stats

.261/.304/.478, 62 HR, 191 RBI, 139 R

Career History

Forced into action in 2011 following an injury to Kendrys Morales, Mark Trumbo hit 29 home runs with 87 RBI as a rookie in 2011.

He appeared to be joining the ranks of the slugging elite in the first half last year, as he hit .306/.358/.608 with 22 home runs and 57 RBI and made the All-Star team.

However, that was followed by a .227/.271/.359 line in the second half, with just 10 home runs and 38 RBI. He's hitting .310 now in the early going this season, and it will be interesting to if the 27-year-old can settle in as a consistent producer.

Los Angeles Dodgers: SP Josh Beckett

Career Stats

132-97, 3.90 ERA, 112 ERA+, 1,770 K, 1,911.1 IP

Career History

The No. 2 overall pick in the 1999 draft, Josh Beckett has had an up-and-down career throughout his time in the major leagues.

At times he's been one of the game's top starters, but on the flip side he has struggled mightily at some points in his career as well.

2005: 15-8, 3.38 ERA
2006: 16-11, 5.01 ERA
2007: 20-7, 3.27 ERA
2008: 12-10, 4.03 ERA
2009: 17-6, 3.86 ERA
2010: 6-6, 5.78 ERA
2011: 13-7, 2.89 ERA
2012: 7-14, 4.65 ERA

If this pattern is any indication, Beckett should be in for a big season in 2013. 

Miami Marlins: RP Jon Rauch

Career Stats

547 G, 42-40, 62-for-93 SV, 3.82 ERA, 466 K, 585 IP

Career History

The big 6'11" Jon Rauch was once a top starting pitching prospect in the White Sox organization, but it was not until he moved to the bullpen full-time with the Nationals in 2006 that he found his place in the big leagues.

Since the start of that season, he's made an MLB-high 507 appearances and posted a 3.71 ERA as one of the top right-handed relievers in the league.

After putting up a 4.85 ERA in 53 appearances with the Blue Jays in 2011, he was terrific for the Mets last season with a 3.59 ERA and 0.988 WHIP over 73 appearances. He has the experience and the track record, but he's been inconsistent over the past few years.

Milwaukee Brewers: 2B Rickie Weeks

Career Stats

.250/.349/.427, 131 HR, 380 RBI, 615 R, 117 SB

Career History

A budding power/speed threat when he first entered the league, Rickie Weeks battled injuries throughout the early portion of his career before breaking out in 2010.

He hit .269/.366/.464 with 29 home runs, 83 RBI and 112 runs scored that season, and the Brewers inked him to a four-year, $38 million extension following the season.

The second baseman appeared ready for a full-blown breakout in 2011 when he hit .278 BA, 17 HR, 39 RBI in the first half. However, an ankle injury limited him to just 27 games in the second half, and he slumped last season to a .230 average, despite hitting 21 home runs and stealing 16 bases.

Minnesota Twins: 3B Trevor Plouffe

Career Stats

.231/.296/.426, 36 HR, 96 RBI, 116 R

Career History

26-year-old Trevor Plouffe came out of nowhere last season to hit 24 home runs in 422 at-bats, while serving as the Twins' primary third baseman.

He was a revelation in the first half, hitting .253 with an .871 OPS and 19 home runs before the All-Star break as a driving force in the middle of the Twins lineup.

Those numbers slipped greatly in the second half, though, as he hit .212 with a .619 OPS and just five home runs after the break. Now the question is which player Plouffe actually is, the one we saw in the first half or in the second half?

New York Mets: 1B Ike Davis

Career Stats

.248/.333/.452, 59 HR, 188 RBI, 165 R

Career History

A first-round pick in 2008, Ike Davis made his big league debut as the Mets' everyday first baseman in 2010, hitting 19 home runs with 71 RBI with a .264 average.

He appeared ready to take his game to the next level in 2011, as he had a .302 BA, 7 HR, 25 RBI line in the first 36 games of the season before an ankle injury ended his season.

He scuffled off the bat in 2012, posting a .618 OPS with 11 home runs in the first half, but he turned it around in the second half with a .902 OPS and 21 home runs. The struggles are back to open 2013 though, and he has a .136 average and .459 OPS to open the season.

New York Yankees: SP Phil Hughes

Career Stats

52-38, 4.46 ERA, 97 ERA+, 539 K, 642 IP

Career History

A first-round pick in 2004, Phil Hughes was one of baseball's top prospects when he joined the Yankees rotation as a 21-year-old in 2007.

After struggling his first two seasons, he found a job at the back end of the Yankees bullpen with a 3.03 ERA and 10.0 K/9 in 51 appearances. He joined the rotation full-time the following season, went 18-8 with a 4.19 ERA and made the All-Star team.

He's gone just 21-18 with a 4.67 ERA the past two seasons, as he's struggled to consistently pitch up to his potential. Now 27, he's allowed 17 hits and eight runs in seven innings of work this season, as the Yankees continue to hope he'll solidify their staff.

Oakland Athletics: CF Chris Young

Career Stats

.238/.318/.436, 134 HR, 417 RBI, 462 R, 116 SB

Career History

A streaky hitter throughout his career, Chris Young has always struck out a ton but has managed to offset that with his power/speed combination.

Last season, he began the year on fire, hitting .410 with five home runs and 13 RBI in his first 11 games. He hit just .158 and .143 in the following two months, though, with a total two home runs and five RBI, before closing out the year relatively productively.

He was traded to the A's in the offseason, and while he's hitting just .192 out of the gates this season, he has a .685 OPS with two home runs, nine RBI and four steals. The numbers will likely be there at the end of the season once again, but it's an up-and-down ride to get there.

Philadelphia Phillies: RP Phillippe Aumont

Career Stats

23 G, 1-3, 2-for-3 SV, 3.00 ERA, 18 K, 18 IP

Career History

The No. 11 pick in the 2007 draft by the Mariners, Phillippe Aumont was traded to the Phillies as part of the Cliff Lee deal prior to the 2010 season.

Originally used as a starter after he was acquired, the team moved him to the bullpen in 2011 where his plus stuff led him to be profiled as a potential future closer.

However, a high walk rate (6.9 BB/9 in 2012) has plagued him throughout his career, and he's already walked six in 3.1 innings of work over five appearances this season. If he can ever refine his command, he has electric stuff, but it remains to be seen if that will happen.

Pittsburgh Pirates: 3B Pedro Alvarez

Career Stats

.231/.306/.414, 50 HR, 170 RBI, 127 R

Career History

The Pirates took Pedro Alvarez with the No. 2 pick in the 2008 draft. He made his debut in Pittsburgh in 2010 when he posted a .788 OPS with 16 home runs and 64 RBI in 95 games.

Expected to emerge as a middle-of-the-order producer, Alvarez hit .191 over 235 at-bats the following season and spent time in the minors.

He provided some pop last season with 30 home runs in 525 at-bats, despite hitting just .244, and it looked as though he would provide some plus power if nothing else. He's hitting just .089 through 45 at-bats this season, though, as he's yet to homer and has just two RBI.

San Diego Padres: CF Cameron Maybin

Career Stats

.248/.311/.369, 30 HR, 131 RBI, 245 R, 85 SB

Career History

One of the key pieces the Marlins acquired from Detroit in the Miguel Cabrera deal, Cameron Maybin was a big leaguer at the age of 20 and looked to have an incredibly high ceiling.

However, he bounced between the minors and majors for three seasons before the Marlins dealt him to the Padres for a pair of relievers. Finally handed an everyday job in San Diego, he hit nine home runs and swiped 40 bases, while posting a 4.2 WAR in 2011 (h/t FanGraphs).

That earned him a five-year, $25 million extension, and he responded by hitting just .212 with a .596 OPS in the first half last season. He rebounded with a .282 average and .735 OPS in the second half, and at 26 years old no one is sure exactly what kind of player Maybin is at this point in his career.

San Francisco Giants: SP Barry Zito

Career Stats

162-133, 3.94 ERA, 109 ERA+, 1,810 K, 2,453 IP

Career History

When Barry Zito hit the free-agent market in 2007, he had a 102-63 career record with a 3.55 ERA and a Cy Young award in seven seasons with the A's. That earned him a seven-year, $126 million deal from the Giants, as he was expected to anchor their staff.

Instead, he went 43-61 with a 4.55 ERA over his first five seasons in San Francisco, as his contract became a cautionary tale for teams thinking of signing a pitcher to a long-term deal.

Just when his days as a useful pitcher seemed over, he went 15-8 with a 4.15 ERA last season and followed that up with a terrific postseason. He went 2-0 without allowing an earned run through his first two starts this season, but allowed nine earned runs in 2.2 innings last time out.

Seattle Mariners: 1B Justin Smoak

Career Stats

.223/.306/.370, 47 HR, 157 RBI, 130 R

Career History

The Rangers took Justin Smoak with the No. 11 pick in the 2008 draft, and he was traded to the Mariners at the deadline in 2010 for Cliff Lee.

Since joining the Mariners, he's hit .226/.304/.374 as he's failed to turn into the middle-of-the-order power threat Seattle hoped he would become.

He shortened his swing in the second half last season and hit .341/.426/.580 with five home runs and 11 RBI in the final month of the year. He followed that up with a terrific spring, but he's hitting just .204 with zero home runs in the early going this season.

St. Louis Cardinals: RP Fernando Salas

Career Stats

165 G, 6-12, 24-for-34 SV, 3.35 ERA, 167 K, 169.1 IP

Career History

Fernando Salas looked like the Cardinals' closer of the future back in 2011, as he took over for Ryan Franklin and converted 24 of 30 save chances with a 2.28 ERA and 9.0 K/9 in his first full season in the majors.

Slotted in a setup role the following season, he went 0-3 with a 6.04 ERA in 28 appearances over the first three months of the season.

He turned things around from there, though, going 1-1 with five holds and a 2.97 ERA in his final 37 appearances with 33 strikeouts in 33.1 innings. Salas is now 27, and the Cardinals are left wondering exactly how good or how bad he can be.

Tampa Bay Rays: RF Matt Joyce

Career Stats

.252/.341/.461, 62 HR, 215 RBI, 201 R

Career History

A .243 hitter who had flashed decent power with a 162-game average of 22 home runs in 493 at-bats, Joyce entered the 2011 season ready to take on an everyday role for the first time.

Thanks to a .414 BA, 7 HR, 21 RBI line in May, Joyce hit .290 with 12 home runs and 41 RBI and made the All-Star team. However, those numbers slipped to .259 BA, 7 HR, 34 RBI in the second half.

It was more of the same last season, as he hit .279 BA, 11 HR, 34 RBI in the first half, but struggled again after the break with a .202 BA, 6 HR, 25 RBI line. In a Rays offense thin on production, Joyce will keep getting chances, but there's no question he's been wildly inconsistent.

Texas Rangers: SP Derek Holland

Career Stats

40-30, 4.60 ERA, 98 ERA+, 483 K, 591 IP

Career History

A 25th-round pick in 2006, Derek Holland went 11-17 with a 5.52 ERA over his first two big league seasons before taking a huge step forward in 2011.

He went 16-5 with a 3.95 ERA and AL-high four shutouts, then turned in a terrific postseason. With the departure of C.J. Wilson in the offseason, Holland was expected to step up as the ace of the Rangers staff next season.

Instead, he was average at best, going 12-7 with a 4.67 ERA and making just 16 quality starts over his 27 starts on the season. He's off to a nice start this year, with a 1.64 ERA and just 13 hits allowed in 22 innings in his first three starts.

Toronto Blue Jays: CF Colby Rasmus

Career Stats

.243/.313/.426, 80 HR, 252 RBI, 314 R

Career History

A highly touted prospect entering the 2009 season, Colby Rasmus was expected to be a franchise cornerstone in center field for the Cardinals.

He looked the part of a future star in his second season in the league, as he hit .276/.361/.498 with 23 home runs and 12 steals in 2010 as a 23-year-old.

The potential is still there, but he continues to be incredibly inconsistent at the plate, as his month-by-month OPS numbers for his career are .857, .729, .853, .641, .648, .661. He's currently leading the AL with 23 strikeouts, but he does have 26 total bases in 14 games.

Washington Nationals: RP Henry Rodriguez

Career Stats

132 G, 5-6, 11-for-18 SV, 4.30 ERA, 140 K, 132 IP

Career History

Originally part of the Oakland organization, Henry Rodriguez was traded to the Nationals for Josh Willingham prior to the 2011 season.

In his first season in Washington, he posted a 3.56 ERA with 70 strikeouts in 65.2 innings as he looked to have a bright future thanks to a blazing fastball that reaches triple digits.

However, last year his ERA spiked to 5.83, and he continued to struggle with his command with a 6.8 BB/9 mark and 1.398 WHIP. The stuff is there for the 26-year-old to be dynamite late-inning arm, but his command has to improve.