Castro went 2-3 with a 3.99 ERA across 15 starts with the Eugene Emeralds. In 65.1 innings he allowed 54 hits, 29 walks and struck out 64. He allowed three homers and induced four double play grounders while holding the opposition to a .223 average.

2007

Castro went 2-6 with a 6.22 ERA over 14 games, including 12 starts, for the AZL Padres. In 50.2 innings he allowed 61 hits, walked 30 and struck out 55. He tied for the league lead in losses.

2006

The right-hander went 1-3 with a 4.63 ERA for the Dominican Summer League (DSL) Padres. In 46.2 innings, he allowed 40 hits, walked 21 and struck out 58. Castro did uncork nine wild pitches and twice tossed two in any game last year. He had a 1.89 ERA in July last year and a 9.00 mark in April and 5.48 ERA in August. Righties hit .208 off him in 2006.