Beckett last pitched on Aug. 17, when he was shelled by the Blue Jays for eight hits and eight runs over 2 1/3 innings.
He was then shut down with right elbow inflammation, which also caused some numbness in two of his fingers.
"He had a real good flat ground and had a real strong bullpen [session]," said Red Sox manager Terry Francona. "He's all set."
The Red Sox were determined to be conservative with Beckett, even if it wasn't the easiest thing to do in the middle of a pennant race.
"We're pretty comfortable that he's ready to go," Francona said. "[He] probably could have pitched the other day. We always try to do things the right way, even when it's not easy to do. I think we're real comfortable that he can go out and pitch and not think about it and go compete instead of throwing a pitch and wondering if it's going to crop up."
Ian Browne is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.