Beckett (11-9) was scheduled to start Friday's contest against the Chicago White Sox, but was scratched after Thursday's 3-1 loss to the New York Yankees. He has not pitched since Aug. 17, when he surrendered eight runs and eight hits in 2 1/3 innings to the Toronto Blue Jays.
Two days later, the team noted on its Web site that Beckett had been dealing with some numbness in two of his fingers. Later, it divulged that elbow inflammation also was part of his problems.
"He's one of our horses and a guy that we count on for a lot of innings," said fellow pitcher Jon Lester. "If his body is telling him that he can't pitch, then he can't pitch. We're going to do our best to pick up his slack (and) we'll just keep rolling."