General manager John Mozeliak said Thursday that any contribution this season from Carpenter, sidelined since February with nerve issues on the right side of his body, would be a bonus. But he said the prognosis has improved the last few days.
"We don't think it's as serious as we first thought," Mozeliak said. "It's slowing things down. Hopefully we can continue to work at it. As you can tell, we've got to be patient here."
Before spring training, the 38-year-old Carpenter and the team believed the injury might be career-ending. The 2005 NL Cy Young winner had been steadily progressing before the back tightened after he finished throwing Sunday.
Mozeliak anticipated the team would have a better handle on the situation after other doctors in St. Louis weighed in on the back issue. He said it was too soon to label starting pitching as a target at the trade deadline, and wasn't ready to dangle top prospects as bait.
The Cardinals had the best record in the majors despite numerous pitching injuries. Jaime Garcia and closer Jason Motte are out for the year and Jake Westbrook missed a month with a shoulder injury, but St. Louis has gotten big contributions from several rookie fill-ins.
"I don't know what our needs will be on July 31st," Mozelilak said. "The good news is, we're playing pretty good baseball and we have six weeks to sort through it."
Carpenter was 21-5 with a 2.83 ERA in his '05 Cy Young season and was second after going 17-4 with a 2.24 ERA in 2009. Before this season, he had missed most or all of five seasons due to shoulder, elbow and nerve injuries.
Last season, he returned from radical surgery to relieve nerve compression in time to help the Cardinals earn the final NL wild card spot. The right-hander is in the final year of a two-year contract.
Two top relievers from the recent past, Mitchell Boggs and Fernando Salas, are in the minors. Boggs, twice demoted after fumbling the job as stand-in closer, is back in the bullpen at Triple-A Memphis at his request after making three starts, and Salas is being prepped for possible multi-inning middle relief.