After returning from elbow ligament transplant in July 2008, Carpenter was again shut down by a nerve condition that prevented his right biceps from firing.

Carpenter subsequently sought multiple medical opinions that were split between surgery and rest. Carpenter ultimately decided against surgery because of its potential risks and returned to lead the National League in ERA in 2010.

The club and Carpenter played down their level of concern last week even as the club contemplated both internal and outside options.

Carpenter, meanwhile, described last week's discomfort as "waves of weird pain I had never experienced before." However, MRI results and Friday's nerve conduction allayed concerns even before the final finding was reached. Well aware of the ramifications of any relapse, Carpenter expressed relief over the latest finding.

"I think we're going to move ahead further in a positive direction," he said.

Originally scheduled to make his exhibition debut Monday, Carpenter will skip the start. Shelby Miller and Jaime Garcia will instead work split-squad games against the Washington Nationals and Atlanta Braves, respectively, with Carpenter's schedule still to be determined.