Carpenter threw a bullpen session on Wednesday after throwing one on Monday, and he will do the same again Friday. After that, he is expected to throw a simulated game Monday.
Head athletic trainer Barry Weinberg and general manager John Mozeliak said through the club's media relations department that Carpenter felt very good after both of his past two throwing sessions.
Carpenter, 33, underwent the operation in July of last season. The typical recovery time for Tommy John surgery is roughly 12 months.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.