"I think I was overthrowing in the last inning and I got a little tired, but that's why -- I threw too many pitches," De La Rosa said.
But he got out of it, which is vintage De La Rosa, manager Walt Weiss said.
"He did what he does so well -- he minimized the inning [and] gets out of it with very little damage," Weiss said. "He was real good at that last year, just pitching his way out of things. A lot of that has to do with his changeup and his ability to keep the ball off the barrel, and that's what he did today."
Despite the long third inning, De La Rosa's overall performance was much better than it was on Sunday, when he surrendered four runs on four hits (one home run) and two walks.
"There's definitely improvement," De La Rosa said. "Especially my fastball command was a little better this time. I have to keep working on my breaking ball, throwing it for a strike."
Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. This story was not subject to the approval of Major League Baseball or its clubs.