In the second trade of the offseason for the White Sox, outfielder Carlos Quentin was shipped to San Diego for a pair of minor league pitchers. Simon Castro, a 23-year-old Dominican, and Pedro Hernandez, a 22-year-old Venezuelan, join the Sox. Both Castro and Hernandez have AAA experience so the two could be pushing for Major League playing time shortly.
Castro has logged 558 innings in six pro seasons and first shot up the prospect rankings following his strong 2009 season. At 21, the 6-5 right-hander struck out 157 and walked 37 in 140.1 innings (3.33 ERA) in the Low-A Midwest League. Baseball America ranked him the 57th best prospect in the game entering 2010.
That year he pitched primarily in AA and handled the jump nicely. His strikeout rate dropped a bit (113 K in 140 IP), but he still just walked 42 so he only dropped one spot in BA's pre-2011 rankings and Project Prospect posted a favorable scouting report of him following the season.
Castro started 2011 with Tuscon in the hitter-friendly Pacific Coast League and got rocked in six starts, forcing a demotion back to AA in mid-May. His control returned there. In 25.2 IP in AAA Castro walked 18. In 89.1 IP in AA, he walked 16. John Sickels had him at No. 35 in his top 50 pitching prospects entering 2011 (two spots behind Zach Stewart) and said "stock down, but still a prospect," after the season but dropped him off his 2012 Padres top 25 prospects.
He needs to refine his mechanics and repeat his delivery better. Good thing the Sox have a pretty good track record in that department. With a 92-94 fastball that has good movement, a good slider and a decent change Castro has a good pitching arsenal. With control issues in mind, he profiles at best as a mid-rotation starter with a better chance of winding up as a No. 4 or No. 5. With Nestor Molina and now Castro, GM Kenny Williams seems to be stockpiling near-Major League ready arms, which is never a bad thing.
As for Hernandez, the ceiling isn't as high, but he's about as close to the Majors. In five minor league seasons he's made 48 starts and 45 relief appearances, but most seem to think he projects as a middle inning reliever. The 5-10 lefty has shown very good control in his career (1.5 BB/9), but also like Castro he couldn't hack it in a short AAA stint. Hernandez pitched in three levels in 2011, finishing the year in AA.
Baseball Prospect Nation has a write up of the trade with some info on Hernandez, who seems to be a pretty under the radar pitcher. Daryl Van Schouwen tweeted "Hernandez is lefty with 3 good pitches for strikes, but leveled off when he reached AAA level." Clearly Castro was the main piece of the trade, but Hernandez gives the Sox some extra relief depth (which they have quite a bit of in the minors already).
Overall, Castro seems like a good get, especially if the Sox can get him to improve his control with some different coaches getting a hold of him. Even after a bad 2011 Castro is a top 10 prospect in the system, and likely top five. Hernandez is certainly in the top 30, but for the most part after the top ten it's personal preference in the White Sox system.
(South Side Sox has a good link on the trade)