"Red Sox second baseman Dustin Pedroia will return to Boston today to have his right knee examined and is facing the possibility of surgery that would sideline him for at least a month.

Pedroia was injured on the first play of the game May 16 when the Orioles' Brian Roberts hit a ball off the chest of Daisuke Matsuzaka. Pedroia fielded the ball and landed on his knee. "I banged it hard and it has been bothering me ever since,'' he said.

He described the procedure, which will be done at Massachusetts General Hospital, as a "needle with a camera on it'' that will determine the extent of the damage. If necessary, Pedroia then would have the surgery immediately.

"It could keep me out a month,'' he said after last night's 11-6 victory against the Yankees. "It's not what I want. But I have to get it checked out. It's been bothering me a lot.''

Pedroia said his lack of production at the plate — he is hitting .247 with a .338 on-base percentage — is attributable to his knee and surgically repaired left foot.

"It's hard to hit with something wrong with your legs,'' he said. "I've been trying.''

If Pedroia is placed on the disabled list, the Sox could use Jed Lowrie at second base and Marco Scutaro at shortstop. Drew Sutton also has experience at second base."