Carpenter threw about 20 pitches, with Minor League pitching instructor Derek Lilliquist catching. Lilliquist got down in a crouch for the throws from Carpenter, who said he wasn't simply lobbing the ball in. The 2005 Cy Young winner will throw again from a mound on Wednesday and Friday, then will probably ratchet up his intensity level a bit next week.
"It was good," Carpenter said. "It was fun. I think I made 20 pitches. I got the ball going down real good. It came out nice. Everything was good."
Up until Monday, Carpenter had only been throwing long toss from flat ground at various distances and intensities. Now long toss simply serves as a warmup for him to get on the mound.
"It was fun to get back out there," Carpenter said. "I'm not firing it, but I'm letting it come out a little bit. It's going downhill with some pop at the end."
Carpenter's target date for a return to pitching in Major League games remains sometime in July. He has encountered no significant setbacks since beginning his rehabilitation.
"He's making progress," manager Tony La Russa said. "I'm no more excited about that than I have been every day I've seen him. He's doing better every day."
"I feel normal," Carpenter said. "There's no stiffness, nothing. So that's a good thing. Sometimes, I still wait to wake up in the morning and go, 'Oh [no], there it is. There's the day they've been talking about.' But I haven't had that day."
The typical rehab time for Tommy John surgery is approximately 12 months for a starting pitcher.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.