One of the best parts of spring training each year is the handful of unheralded players who turn heads with an unexpected start to the season.
Whether it is a top prospect proving he's capable of hanging with the big boys or a journeyman veteran making a strong case to be part of the Opening Day roster, surprising spring performances are always fun to watch.
Here is a look at 10 pitchers who have turned in surprisingly dominant performances early on this spring.
Spring Stats: 2 G, 5 IP, 1 H, 0 ER, 0 BB, 6 K
Originally a member of the Padres, LeBlanc went 17-22 with a 4.54 ERA in four seasons with San Diego before being traded to the Marlins for catcher John Baker last offseason.
LeBlanc opened last season in the minors before joining the Marlins bullpen in July. He was eventually moved to the rotation when Carlos Zambrano struggled, and all told he went a combined 2-5 with a 3.67 ERA in 25 appearances (nine starts).
Ricky Nolasco and Henderson Alvarez will front the Marlins rotation, but LeBlanc has put himself in a good position to break camp as the team's No. 3 starter with his strong start to the spring.
Spring Stats: 3 G, 7 IP, 3 H, 1 ER, 3 BB, 2 K
A third-round pick by the Angels in 2005, O'Sullivan made his big league debut at 21 years old as he went 4-2 with a 5.92 ERA over 10 starts.
The following season he was traded to the Royals in the deal that shipped Alberto Callaspo to the Angels, and he struggled to a 6.63 ERA over 23 starts in Kansas City.
He spent all of last season in Triple-A, going 14-7 with a 4.23 ERA, and he signed a minor league deal with the Padres this winter. With the starting rotation wide open beyond Edinson Volquez and Clayton Richard, he has a real shot at earning a spot if he keeps it up, especially with Freddy Garcia struggling.
Spring Stats: 3 G, 3 IP, 1 H, 0 ER, 0 BB, 7 K
A third-round pick by the Reds in 2009, Joseph was acquired by the Royals at the deadline last season for reliever Jonathan Broxton.
In 55 minor league appearances last season, he posted a 2.33 ERA and recorded 20 saves while striking out 87 hitters in 69.2 innings of work.
He enters the season as the No. 14 prospect in the Royals organization according to the Baseball America Prospect Handbook, and he has a real chance to be the team's closer of the future.
Spring Stats: 3 G, 6 IP, 1 H, 0 ER, 3 BB, 4 K
One of the three players acquired from the Angels at the deadline last season for Zack Greinke, Hellweg was a nice find by Los Angeles in the 16th round back in 2008.
The 24-year-old was stretched out to start last season, going 7-11 with a 3.29 ERA, but his future could be in the back end of the bullpen.
With a fastball that sits in the mid-90s and can be dialed up to triple digits when he pitches out of the bullpen, Hellweg has a bright future, and he could find himself in Milwaukee at some point this season.
Spring Stats: 2 G, 5 IP, 2 H, 1 ER, 2 BB, 9 K
A middling prospect in the Indians rotation, Nuno was released in March 2011. He's turned things around since joining the Yankees though, and while he's no top prospect, he has value.
The 25-year-old went 10-6 with a 2.54 ERA in 31 appearances (21 starts) between High-A and Double-A last season, and if he pitches well in a full season in the high minors, he could be in the Bronx at some point in 2013.
The odds are stacked against him to make the Yankees' Opening Day roster with Boone Logan and Clay Rapada filling the left-hander roles in the 'pen, but if injury strikes, he could be next in line on the southpaw depth chart.
Spring Stats: 2 G, 5 IP, 2 H, 0 ER, 1 BB, 8 K
Acquired from the Padres last season in the Carlos Quentin trade, Castro was one of Baseball America's Top 100 prospects prior to the 2010 and 2011 seasons.
He struggled in 2011, but turned things around with a solid season last year as he went 7-5 with a 3.85 ERA between Double-A and Triple-A.
The 24-year-old enters the season as the No. 20 prospect according to Baseball America Prospect Handbook, and while he is a bit farther down the depth chart, he could move up quickly if he keeps pitching like he has.
Spring Stats: 2 G, 4 IP, 2 H, 0 ER, 0 BB, 4 K
Once the ace of the Rays' staff, Kazmir last appeared in a big league game on April 3, 2011, and he's not been a good option since the 2009 season.
He spent last season pitching in the Independent League, going just 3-6 with a 5.34 ERA over 14 starts for the Sugar Land Skeeters.
The No. 5 spot in the Indians rotation is wide open right now, and he's impressed so far in camp. It's hard to believe he's still only 29 years old, and it's not out of the question that he could regain his once-dominant form.
Spring Stats: 3 G, 4 IP, 3 H, 0 ER, 1 BB, 8 K
An unheralded 31st-round pick back in 2008, Magill has moved slowly through the Dodgers system, and the 23-year-old turned in a solid season in Double-A last year.
The right-hander went 11-8 with a 3.75 ERA and 168 strikeouts in 146.1 innings for Chattanooga, and that was enough for him to be added to the 40-man roster earlier this offseason.
With veterans Chris Capuano, Aaron Harang, Chad Billingsley and Ted Lilly already battling for one rotation spot, Magill will have a hard time breaking through in 2013, but his future looks bright.
Spring Stats: 2 G, 5 IP, 4 H, 0 ER, 2 BB, 8 K
Though he's been in the shadow of fellow prospects Tyler Skaggs and Trevor Bauer the past year-and-a-half, Corbin is a solid young pitcher in his own right.
He pitched well as a rookie last season, going 6-8 with a 4.54 ERA over 22 appearances (17 starts), but he still entered camp on the outside looking in for a rotation spot.
Skaggs was expected to be the team's No. 5 starter, and while he has a higher ceiling than Corbin, it may be Skaggs who winds up as the odd man out if the 23-year-old Corbin keeps pitching like he has.
Spring Stats: 3 G, 7.2 IP, 4 H, 0 ER, 1 BB, 11 K
The No. 19 pick in last June's draft, Wacha has created more buzz this spring than perhaps any other player in the league as he's been nothing short of dominant.
That's right in line with how he pitched after signing last summer, as he made 11 appearances and posted a 0.86 ERA with 40 strikeouts in 21 innings of work, climbing three levels and reaching Double-A.
He's been praised league-wide on his early returns this spring, but no praise may be more telling than that of catcher Yadier Molina (h/t MLB.com):
"I think that guy, right now, can pitch in the big leagues. That's the way I look at it. He has great stuff. He has a great presence on the mound. He has great command, a great attitude."
Awfully high praise coming from someone of Molina's stature, and while the 21-year-old is all but a lock to open the season in the minors, he could be knocking on the door by midseason.