06/08/2013 10:47 EDT | Updated 08/08/2013 05:12 EDT

Red Sox RHP Clay Buchholz leaves in 7th with apparent injury

BOSTON - Red Sox starting pitcher Clay Buchholz walked off the mound in the seventh inning in the nightcap of a day-night doubleheader Saturday night with what the team called "neck tightness."

Buchholz had attempted to field Howie Kendrick's hard grounder to the box an inning earlier, had the ball bounce behind him and when he left after the sixth he was seen on TV looking at his left hand with a trainer.

It was quite a fielding night for the Red Sox ace.

He also rolled over on his side and made a tag after bobbling Alberto Callaspo's high-chop grounder near first before making a tag in the fourth.

With two outs in the seventh, manager John Farrell and a trainer came to the mound. After a brief discussion, Buchholz walked off and was replaced by Craig Breslow.