De La Rosa only made three rehab starts, so this outing was scheduled to be a short one as Arizona aims to build the right-hander back up to 70 pitches before the end of the season.
In his first inning back, De La Rosa retired the Giants in order, striking out Buster Posey to end the first. He allowed a run on a sacrifice fly by Eduardo Nunez in the second, but stranded San Francisco baserunners on first and second to end the inning.
De La Rosa allowed one hit with two walks and three strikeouts. He threw 43 pitches, 23 for strikes.
"Everything feels fine," De La Rosa said. "Next outing, I guess, is like 60, 65 and I think one more outing I should be ready to go up to 70, 75."
Before going on the DL, De La Rosa was proving to be an effective starter for the D-backs. The 27-year-old has been both a starter and reliever in his career. In six starts before getting injured, De La Rosa was finally finding consistency in the rotation, posting four quality starts in that stretch.
"He threw a really good fastball, slider," Arizona catcher Welington Castillo said. "He seemed like the Rubby that he was before he got hurt, so that's really good."
Jake Rill is a reporter for MLB.com based in Phoenix. This story was not subject to the approval of Major League Baseball or its clubs.