Cameron, Ellsbury on the mend

Boston Red Sox outfielder Mike Cameron, who missed Thursday's game against the Twins due to abdomen pain, passed a kidney stone Friday morning, manager Terry Francona said, and while he is not in Friday's lineup, amazingly he was out on the field Friday afternoon doing some light jogging.

"I don't know if it's ambitious or not,'' Francona said, "but he might play tomorrow.''

Cameron spent Thursday night in a Minneapolis hospital for observation before returning to Boston.

"He must have unbelievable pain tolerance,'' Francona said.

Meanwhile, Jacoby Ellsbury underwent another set of X-rays Friday that came back negative, confirming the original diagnosis of bruised left ribs. After extensive discussion, the decision was made not to place Ellsbury on the disabled list.

"We tried to pinpoint with him where he thought he was,'' Francona said. "It may be a little ambitious that he'll play in the next couple of days, but if we put him on the DL we risk losing four, five, six days of Ellsbury.''

That decision will be re-evaluated Saturday, Francona said, and may depend in part on Cameron's availability.

Bill Hall was in center field again Thursday, with Jeremy Hermida in left. The emergency outfielder is Kevin Youkilis. "I don't think that makes his day,'' Francona said.

A factor in the decision not to disable Ellsbury may have been the fact that rookie Josh Reddick, the logical replacement, had just four hits in 29 at-bats in Pawtucket, although Francona did not mention that as a consideration.

Gordon Edes is ESPNBoston.com's Red Sox reporter. He covered the Red Sox for 12 years and has reported on baseball for 25 years. Ask a question for his next mailbag here.