"It's just precautionary. We're not taking a chance," Mattingly said of Kershaw's minor setback. "He's on schedule for his first start. The bullpen [session] is Friday, at least it's scheduled for Friday. He's able to do everything. He wanted to do the first bullpen [session Wednesday], but we're not letting him, just because he didn't want to miss the first day of school."
Kershaw felt tightness in workouts in the days leading up to the opening of camp this week. Named to start the spring opener, Kershaw lobbied to pitch, but was overruled by the medical staff.
Joining Kershaw on the precautionary list is reliever Mike MacDougal, who felt a twinge in his back during fielding drills on Wednesday and was scratched from his Thursday bullpen session. Mattingly said trainer Sue Falsone did not believe the injury was serious, and MacDougal, like Kershaw, was expected to participate in all other drills on Thursday.
The Dodgers also announced that non-roster invitee Jose Ascanio failed his physical. Ascanio, 26, missed the 2010 season with shoulder surgery and spent most of '11 at Triple-A. He had an eight-game callup with Pittsburgh, where he posted a 7.11 ERA.