Middlebrooks leaves with spasms in lower back

BOSTON -- Red Sox third baseman Will Middlebrooks exited Thursday night's game against the Indians with lower back spasms.

When the Red Sox went out for defense to start the fifth inning, Pedro Ciriaco replaced Middlebrooks, who struck out looking in his two at-bats, the latter of which was in the fourth inning, just before he came out of the game.

"His back started to tighten up throughout the course of tonight's game," said Red Sox manager John Farrell. "This is unrelated to the rib injury that he was dealing with in the collision with the wall 10 days ago or so. In his last at-bat last night in Chicago, I think he slipped a little bit coming out of the box, but didn't mention any complaint prior to the game tonight. As things unfolded, the stiffness was there, so he's day to day right now."

Middlebrooks is a player the Red Sox can ill afford to be without for a significant length of time. Third base is not a position of strength for Boston in the upper Minors.