MEMPHIS, Tenn. -- Cardinals right-hander Chris Carpenter said he felt "pretty good" after throwing a bullpen session Friday afternoon at Auto Zone Park. He remains on pace to make his first regular-season start on Thursday against the Pittsburgh Pirates at Busch Stadium.

Carpenter was scheduled to start Friday night's game against the team's Triple-A affiliate, the Memphis Redbirds, but was scratched earlier in the week after his left calf tightened up on him both during his previous start Sunday against Minnesota and more severely again during a Monday morning run.

"I still feel it a little bit," Carpenter said of the pain. "But I would say that if Monday or Tuesday was a 10 [in terms of pain], then today is a 0.5 compared to what it was."

Carpenter, whose well-documented injury troubles allowed him to make just four starts the past two seasons, was 2-1 with a 1.52 ERA in 23 2/3 innings this spring. He allowed all four of his earned runs in his final start in Fort Myers, Fla., and felt good enough to make the start Friday night, but was held back when the team decided it would be smarter to err on the side of caution.

"If I had to take my turn today, I would have," Carpenter said. "But I don't have to."

Carpenter, who will throw another bullpen session on Monday, is one of the Cardinals' biggest keys heading into the 2009 season. The 2005 National League Cy Young Award winner made just three starts in '08 for a team that won 86 games and missed out on a playoff spot by four games -- making the decision to hold him out of a meaningless exhibition game that much smarter.

"It would be a huge plus for us if he takes the ball regularly from now until Halloween," manager Tony La Russa said. "He's as good as anybody pitching in any starting rotation anywhere."