Beckett made several warmup tosses before that start against the Marlins, but he left the mound without making an official pitch.
Red Sox manager Terry Francona said Beckett is expected to throw from 60 feet on flat ground on Sunday.
"His workouts, he's feeling good," Francona said. "He's been doing all his arm exercises, everything like that. Now we'll just get him back playing catch on flat ground. That's good. We wanted him to. [The Red Sox's medical staff] thought it would be a week, and they were right about on. So that's good."
Francona said Beckett, who went 20-7 with a 3.27 ERA for the Sox in 2007, is looking forward to being able to throw again.
"He's not used to people putting reins on him," Francona said. "He's a pretty good worker, so he doesn't feel like he's working and that's hard for him to understand that. But he's done a pretty good job of it."
Though it's doubtful Beckett will be able to pitch on Opening Day in Tokyo, the Red Sox have yet to officially rule it out.
Maureen Mullen is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.