After going 5-2 with a 2.74 ERA in his first 16 appearances of 2010 with Double-A San Antonio, the big right-hander was tabbed as the starting pitcher for the World Team in the XM Futures Game.
"I think I'm doing a fine job in Double-A," the 22-year-old said. "I've really worked for this and I'm really happy to be here."
For the Dominican native, it's been an uneven ride up the Padres system, with several hiccups between rookie ball in 2006 and Class A in '07, '08 and '09. Mixed in with some significant control problems was a brilliant no-hit performance August 17 for Class A Fort Wayne.
After finishing last season with a 10-6 record and a 3.33 ERA in 28 games (27 starts), Castro has kept on track this season with his control and command, with 76 strikeouts and 27 walks in 85 1/3 innings this year.
"I've been improving a lot," he said. "We've really made some progress."
Before the Futures Game at Angel Stadium, the glow of pitching in a Major League venue was evident. Perhaps a bit amped up, Castro gave up two runs on two hits and a walk in his only inning of work, taking the loss in a 9-1 defeat of the World Team against the U.S. squad.
"I didn't feel satisfied, because I know I can do better than that," he said. "But I feel good because this is a great experience and I know better days will come. Being on a Major League mound is really exciting."
So, does getting a taste of big league atmosphere make him want to get to the "show" even more?
"We're working to see if this year or next year the call will come. Everyone comes here with the thought that this could be his year to make the big leagues. That will always be the goal."
David Venn is the senior editor of LasMayores.com, MLB.com's Spanish Web site. This story was not subject to the approval of Major League Baseball or its clubs.