The righty has felt well during his Minor League rehab assignment for Triple-A Pawtucket. He earned the win in a playoff game on Thursday, throwing 1 1/3 shutout innings.
Atchison's recovery from a UCL injury continues to be impressive, since he and the team both feared at one point he was going to need to undergo Tommy John surgery.
"It's going good," Atchison said. "I feel good -- arm feels good. I'm bouncing back and feeling good the next day. I got some good results, and that makes it a little easier. But like I said, everything feels good, and I'll just keep moving forward."
Before sustaining his injury right after the All-Star break, Atchison was one of Boston's best pitchers, going 2-1 with a 1.76 ERA in 37 games.