JUPITER, Fla. (AP) -- St. Louis pitcher Chris Carpenter has returned to the Cardinals' spring training camp, with manager Mike Matheny still unsure when his ace will be back on a mound.
Carpenter, who has yet to pitch in a spring training game, underwent four days of tests last week in St. Louis to determine the cause of a nerve ailment that has weakened his throwing shoulder. Matheny thinks the right-hander will have to rest.
"I've been there before," Matheny said Monday. "When I had the concussion stuff they were flying me all over the country trying to get me to this specialist and that specialist, and sooner or later I just said: Enough, hopefully you guys have the information you need. He understands the process, but it's kind of grueling as far as the poking and prodding."
The 37-year-old has not faced hitters since batting practice on March 3. A bulging disk in his neck originally was thought to be the cause of the problem.
The 2005 NL Cy Young Award winner was 11-9 last season, then went 4-0 in the postseason as the Cardinals won the World Series. He threw 273 1-3 combined innings between the 2011 regular and postseasons.