Alex Caldera was originally acquired by the Royals in the 13th round of the 2007 draft. Through four seasons in the minor leagues, the 25-year-old sports a 27-24 record with a 3.78 ERA in 85 games (including 78 starts).
Caldera turned in his best performance during his full season debut in 2008, when he led the Midwest League champion Burlington Bees in victories, innings pitched, and strikeouts. He finished the year 12-6 with a 2.89 ERA, and he fanned 120 batters while walking just 36 in 149.1 innings pitched. Following that season, Royals Corner ranked Caldera as the organization's 30th-best prospect on our annual Top 60 list.
Making the jump to High-A in 2009, Caldera struggled during his first shot at the Carolina League, limping to the finish line with a 5-10 record and a bloated 4.77 ERA. He repeated Wilmington in 2010 and pitched much better, earning a midseason promotion to the Double-A NW Arkansas Naturals, for whom he went 3-2 with a 5.12 ERA in eight appearances.
Caldera figured to repeat Double-A this season, but the Royals' starting pitching depth in the upper minors likely would've forced him into a piggyback or bullpen role. At his best, Caldera is a control pitcher with a slightly below average fastball, and his repertoire doesn't profile particularly well in a relief role. However, with the Nationals, he seems likely to begin the season in the Double-A Harrisburg Senators' rotation.