Former Top MLB Prospects Who Could Make or Break Their Team's 2015 Hopes

Being a top prospect on a contending team brings with it a lot of hope and expectation. No wonder many highly regarded youngsters don't get it right the first time around.

Hey, not everybody can be Mike Trout, Yasiel Puig or Jose Fernandez and live up to the hype right away.

But just because they no longer qualify as rookies, young major leaguers who at one point were elite prospects—measured here by placing in Baseball America's Top 100 over the years—often will wind up figuring it out and turning things around.

Here's a batch of such players on contenders (or could-be contenders) who haven't yet but very much still could—and maybe even will—make good on their pedigree and promise. If that happens, it'll mean big things for both themselves and their teams in 2015.

Because this is about not-entirely-fulfilled potential, none of the following still-young former top prospects has yet to register a season worth 2.0 wins above replacement, a standard considered starter-worthy, per FanGraphs.

That's why you won't see the likes of, among others, Billy Hamilton, Kolten Wong, Yasmani Grandal and Kevin Gausman, all of whom already have reached that mark.

You will, however, see...

Jimmy Nelson, RHP, Milwaukee Brewers

Morry Gash/Associated Press

Number of Times on BA Top 100: 1

Highest Ranking: No. 96 (2014)

Best Single-Season WAR: 0.8 (2014)

The Milwaukee Brewers were suprise contenders for most of 2014, and if they're going to pull off the same feat this year, look for Jimmy Nelson to play a key role.

The 25-year-old right-hander was more bad than good after coming up in the middle of last year (4.93 ERA, 1.48 WHIP), but he showed enough flashes that the Brewers were willing to trade Yovani Gallardo—the franchise's all-time strikeout leader—in January.

That opened up a spot in the rotation for Nelson, who needs to prove his success at Triple-A, including a 1.46 ERA, 0.92 WHIP and 9.2 strikeouts per nine innings a year ago, can translate to The Show.

Avisail Garcia, Of, Chicago White Sox

Reinhold Matay/Associated Press

Number of Times on BA Top 100: 1

Highest Ranking: No. 74 (2013)

Best Single-Season WAR: 0.2 (2013)

The Chicago White Sox won only 73 games in 2014, but an efficient offseason has them looking like arguably MLB's most-improved club and possible AL Central contenders heading into the season. 

While Avisail Garcia, the primary return in the Jake Peavy trade in July 2013, isn't one of those brand-newcomers, he's still relatively new in town after missing much of last year with injury. And the 23-year-old could be as impactful as any of the White Sox's winter acquisitions, including Jeff Samardzija, David Robertson, Melky Cabrera or Adam LaRoche.

Chicago could use Garcia's potent right-handed bat and capable glove more than ever now that Dayan Viciedo has been released. If Garcia, who has never played more than 72 games in the majors, can stay healthy and produce behind Jose Abreu, this offense is going to be that much better off—and the division will be on notice.

Rougned Odor, 2B, Texas Rangers

Tony Gutierrez/Associated Press

Number of Times on BA Top 100: 1

Highest Ranking: No. 42 (2014)

Best Single-Season WAR: 0.5 (2014)

Sure, you're aware of Rougned Odor, but quite possibly only because of his fun-to-say name. Well, the second baseman is going to make, ahem, a name for himself with his play in 2015.

Despite being stuck behind former consensus top prospect Jurickson Profar on the Texas Rangers depth chart, Odor rocketed to the bigs by age 20 last May in part because Profar's injured shoulder cost him all of 2014.

Although Odor started out slow, posting a .687 OPS in the first half, he wound up turning it up a notch in the second half with 18 extra-base knocks, including six homers over 61 second-half games. That's quite a bit of pop for a little guy who checks in at 5'11", 170 pounds.

Now that Odor has the inside track on the starting second base job, he has the talent and skill set to run with it and help the Rangers—who can't possibly be as injury-prone again—get back to contention in the AL West.

Wilmer Flores, SS, New York Mets

Hunter Martin/Getty Images

Number of Times on BA Top 100: 3

Highest Ranking: No. 47 (2009)

Best Single-Season WAR: 1.3 (2014)

In case you haven't been paying attention, a lot of folks seem to think the New York Mets need to find a shortstop. That's the reason they've been mentioned this winter as a party of interest for top-tier talents like Troy Tulowitzki and Ian Desmond.

There's a lot on the shoulders of Wilmer Flores, who few consider a good enough defender to handle the position full-time for an entire season. Nonetheless, he will get a chance to do so, according to general manager Sandy Alderson.

"I'm real proud of myself because playing shortstop in the big leagues, I didn't think I could do that," Flores said via Kevin Kernan of the New York Post. "Last year went very well. I’m doing everything I can to get better. Now that I have the opportunity to play, I’m going to make the most of it."

Flores had been on the prospect scene for what seemed like forever until finally graduating to the majors last year, but he's still only 23 years old and has an intriguing offensive profile thanks to a career .294/.340/.439 line in (count 'em) seven minor league seasons.

The Mets need Flores to pan out—both with the stick and especially the glove—because they don't have many other options at short for 2015 (Ruben Tejada? Matt Reynolds?), and the goal is to return to relevance after six consecutive losing seasons.

Fellow former Top 100 prospects Travis d'Arnaud—who made five appearances on the BA Top 100, peaking at No. 17 in 2012—also merits mention, and he did appear to start putting it together over the second half (.265 BA .474 SLG and 24 XBH). But if d'Arnaud falters or gets hurt again (his specialty), New York at least could turn to Kevin Plawecki to take over at catcher soon enough.

Didi Gregorius, SS, New York Yankees

Rick Scuteri/Associated Press

Number of Times on BA Top 100: 1

Highest Ranking: No. 80 (2013)

Best Single-Season WAR: 1.4 (2013)

The second New York shortstop in a row, there's even more pressure on Didi Gregorius, who is simultaneously trying to prove himself in the majors after two so-so season with the Arizona Diamondbacks and replace New York Yankees legend Derek Jeter.

While the latter isn't going to happen, the former could, especially if Gregorius, who turns 25 on Feb. 18, plays his above-average defense—something the club never had with Jeter—and makes some gains at the plate on his .243/.313/.366 career line.

"Jeter is still Jeter," Gregorius said in December, according to Anthony McCarron of the New York Daily News. “Everything everybody is going to talk about is Jeter. I’m learning. Just try to focus on the game and win every game."

The glove work at a premium position alone could make Gregorius a three- or even four-win improvement over what the 40-year-old Jeter was able to offer in his final season, when he was the 10th-worst everyday position player in baseball.

Add in the Yankees' need for youth and athleticism, and Gregorius is one of the more important pieces for a club that's hoping to avoid a third straight October-less season.

Javier Baez, 2B/SS, Chicago Cubs

David Zalubowski/Associated Press

Number of Times on BA Top 100: 3

Highest Ranking: No. 5 (2014)

Best Single-Season WAR: -0.8 (2014)

For all the talk and hype around Kris Bryant, arguably the game's top prospect, Javier Baez will be just as important to the Chicago Cubs in 2015.

Baez, 22, showed his awesome power as a rookie, smashing nine homers in 52 games after debuting last August. But he also whiffed a ridiculous 41 percent of the time—a rate that is embarrassingly high. Still, Baez's immense, game-changing oomph would make the Cubs a lot more dangerous.

With Bryant set to take over at third base, Starlin Castro locked in at short, Baez will be battling newcomer Tommy La Stella at second, so it's incumbent upon him to prove he can make enough contact and play solid enough defense to find a role with the Cubs in 2015.

Otherwise, there's a risk that Baez could be in an even tougher spot once top shortstop prospect Addison Russell is ready, perhaps by midseason.

Carlos Martinez, RHP, St. Louis Cardinals

Charlie Neibergall/Associated Press

Number of Times on BA Top 100: 3

Highest Ranking: No. 27 (2012)

Best Single-Season WAR: 1.2 (2014)

After spending the majority of his first two seasons in the majors working in relief, Carlos Martinez is about to get his chance to shine as a starter.

St. Louis Cardinals GM John Mozeliak said this offseason that the No. 5 spot in the rotation is Martinez's to lose entering camp. The 23-year-old nearly made the five-man with a nice spring last year, but ultimately, the job went to Joe Kelly.

But now that Kelly and fellow right-hander Shelby Miller (traded to the Atlanta Braves) are no longer around, the onus is on the undersized Martinez, who has been strangely hittable despite such electric stuff (9.3 H/9 career), to not only hold up under a starter's workload but excel in the role.

Trevor Bauer, RHP, Cleveland Indians

Mark Duncan/Associated Press

Number of Times on BA Top 100: 3

Highest Ranking: No. 9 (2012)

Best Single-Season WAR: 1.5 (2014)

It's not that Trevor Bauer has been bad across parts of three MLB seasons, but he has been disappointing and enigmatic so far, especially considering he was selected No. 3 overall in the 2011 draft.

As a rookie in 2014, the 24-year-old showed his mid-90s fastball and plus curveball could get the job done, but he was plagued by inconsistency, not only from game to game but even inning to inning.

All in all, Bauer's final numbers last year were passable (4.18 ERA, 1.38 WHIP and 8.4 K/9), but one gets the feeling there's more in there if he can just improve his command and control. Now that he's ready for a full season following 153 innings in 2014, a more stable Bauer would be a boost for an underrated Indians rotation that has the potential to be one of the best in baseball.

And in case you're wondering, rotation-mate Carlos Carrasco, who was a top-100 prospect on three occasions in the late aughts, would have been another candidate for this list, but he surpassed the two-win threshold last year when he put it all together in the second half (1.72 ERA, 0.90 WHIP, 9.8 K/9). Finally.

Nick Castellanos, 3B, Detroit Tigers

Paul Sancya/Associated Press

Number of Times on BA Top 100: 4

Highest Ranking: No. 21 (2013)

Best Single-Season WAR: -0.5

In the wake of Victor Martinez's knee injury that could keep him out for the first few weeks of the regular season, per Jason Beck of MLB.com, the Detroit Tigers suddenly could be counting much more on Nick Castellanos.

Thing is, Martinez's surgery to repair a torn meniscus isn't the Tigers' only concern. They also are dealing with another offseason of recovery from Miguel Cabrera and the possibility that what J.D. Martinez did last year (.315/.358/.553) is unrepeatable.

And that's just on the offensive side of things. Don't forget, they lost right-hander Max Scherzer, traded Rick Porcello and are watching the continued decline of Justin Verlander. In short, the Tigers' run of four straight AL Central crowns is in jeopardy.

As a rookie in 2014, Castellanos was underwhelming on offense, posting a .259/.306/.394 triple-slash line, and downright disastrous on defense, as his -30 defensive runs saved ranked dead-last among all hot cornermen by rather a lot.

But Castellanos has it in him to be up to the task. Heading into his age-23 season, he's young enough to get better on D, especially now that he can settle in at third base after shifting back there from left field.

As for his bat, Castellanos finished with the second-highest line-drive rate in the sport (28.5 percent), which indicates he's capable of squaring up and hitting the ball with authority.

Castellanos could be in for a dramatic improvement in Year 2, and Detroit certainly could use it.

Statistics are accurate through the 2014 season and courtesy of MLB.com,Baseball-Reference.com and FanGraphs unless otherwise noted.

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