The right-hander didn't pitch after June 16 because of a stress fracture in his lower back, but general manager Ben Cherington said Buchholz is well on the way to recovery.
"Well, first of all, he was in instructional league and pitched a couple times in instructional league," Cherington said. "That went very well. No issues. He's been in Arizona since then and had no issues. He's started working out.
"He hasn't started a throwing program. We wouldn't do that at this point in the offseason. But he feels good. He has no symptoms. He says he can do everything. He's going to be working out with [Dustin] Pedroia this offseason in Arizona. We're optimistic that he's going to be able to be good."
The Red Sox badly missed Buchholz down the stretch in 2011. He was one of the best pitchers in the American League the year before, going 17-7 with a 2.33 ERA.