Beckett scratched from Sunday start
Beckett left Tuesday night's game against Detroit after 2 2/3 innings because of a back spasm.
Red Sox manager Bobby Valentine said Friday that he didn't think the right-hander will go on the disabled list. Beckett is 5-9 with a 4.54 ERA in 18 starts this season.
"Still stiff," Valentine said. "He worked out, but he's still stiff."
Left-hander Franklin Morales will start in Beckett's place Sunday, his sixth start this season.
Valentine doesn't think Beckett can pitch Monday.
"I don't know about Tuesday," the manager said. "He might miss a whole start or he might slot in. We're trying to see how everybody else gets with Josh's recovery. But he hasn't thrown a ball yet. It's kind of silly to say when he's going to pitch in a game."