Boston forward Brian Scalabrine will be out indefinitely after suffering his second concussion in three days.

"He got hit in the head, and he just had a mild concussion," Coach Doc Rivers said. "I don't know if he was out but he was close. He'll be out probably for quite some time because of that, would be my guess, for quite some time."

Scalabrine was hit in the head during Sunday's win over the Mavericks and suffered the second concussion after being hit by teammate Patrick O'Bryant in practice on Tuesday.

"It just looked like he got hit in the head," Ray Allen said. "I know he got hit last game in the head. He went down and just stayed down and looked disoriented."