Jimmy Rollins will head back to the disabled list with a right calf strain after re-injuring it in last night's game. Wilson Valdez, who was designated for assignment to make room for Rollins at the beginning of the homestand, takes his spot on the roster. Rollins has appeared in only a dozen games this season. Beerleaguer: I heard a doctor describe the restorative scar tissue the body generates to heal a partially torn muscle as the rubber band you find behind a radiator. It seems fine, but you can't trust it. That's what happened here. Rollins essentially skipped his rehab assignment, and it was a mistake.