De La Rosa walked two batters and was charged with two runs in two-thirds of an inning Wednesday in his 2012 debut. He underwent Tommy John surgery on Aug. 9, 2011, and it was his first appearance since July 31 last year.
The hard-throwing pitcher, who is one of the Dodgers' top prospects, has had his name mentioned in trade rumors surrounding the Red Sox.
Castellanos made his Major League debut on May 31. He went 3-for-21 in 11 games with Los Angeles before being sent back down. He batted .347 with 17 homers, 52 RBIs, 25 doubles and seven triples in 86 games at Triple-A.
Alex Angert is an associate reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.