He signed with the Dodgers in 2007 and spent two seasons with their Dominican Summer League team. He was transferred to the Arizona League Dodgers in 2009 and then split 2010 between the Class-A Great Lakes Loons and Double-A Chattanooga Lookouts. Overall, he pittched in 22 games in 2010, with 13 starts and was 7-2 with a 2.37 ERA. He was selected as the Dodgers "Minor League Pitcher of the Year" and given an invite to Major League spring training for 2011. He was assigned back to Chattanooga to start the season, where he was 2-2 with a 2.92 ERA in 8 starts for the Lookouts. De La Rosa was selected to the 2011 Southern League All-Star game, but was unable to participate because he was promoted to the Dodgers.
He was called up by the Dodgers on May 24, 2011. He made his debut the same day, pitching a scoreless eighth inning against the Houston Astros, retiring the side in order, including 2 strikeouts. On May 27, he recorded his first career major league victory against the Florida Marlins.
On June 7, 2011 De La Rosa made his first career start against the Philadelphia Phillies.  He walked five of the first eleven batters he faced but settled down to allow just one run in five innings to pick up the win. rticle here!