Beckett threw during Monday's off-day from 120 feet and was monitored by pitching coach John Farrell.
"That was his third day in a row, so today's a real light day," said manager Terry Francona.
Boston's ace will throw again Wednesday and Thursday, eventually stretching out to 150 feet, and then Friday will serve as another low-key day. From there, the club will see how he feels.
When Beckett (1-1, 7.29 ERA in eight starts) returns is still up in the air.
After the long-toss sessions, a bullpen session would be next.
"That would be the next step," Francona said. "I think we'd really want to be aggressive with his long toss. When you start getting out to 150 [feet], he's got to let [it] loose pretty good. How often we do that, a lot of it's just going to depend on how he feels. I don't think that you're back to a Spring Training [status], just because he's got innings under his belt. But at the same time, you can't shortcut it too much. But we don't want to rush him back and lose [him].
"He's working hard now so he can come back and pitch effectively and feel healthy and all the things we always say, because we believe in them. So we don't want to shortcut anything either."
Maureen Mullen is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.