"I didn't feel the grip," said Doubront. "My changeup was bad. I left the pitch over the plate. One of those days."
Over 3 2/3 innings, Doubront was pounded for 10 hits and seven runs. He walked three and struck out two.
Doubront had fired six scoreless innings over his first two outings.
"Delivery was a little bit tough because my release points and my mechanics weren't right," Doubront said. "I don't know if it's too fast or too slow but it was better for a couple of pitches, then I went back to the wrong mechanics. It's a thing I have to work on."
Ian Browne is a reporter for MLB.com. Read his blog, Brownie Points, and follow him on Twitter @IanMBrowne. This story was not subject to the approval of Major League Baseball or its clubs.