SAN DIEGO -- The Cardinals acknowledged that Chris Carpenter had a brief delay in his rehabilitation from Tommy John reconstructive elbow surgery recently, but the club said that its ace is back on track after only a brief bump.

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.