WALTHAM - At first, Doc Rivers thought Ray Allen was playing around. It was a run-of-the-mill handoff drill. Allen was supposed to take the ball from Kendrick Perkins. Next thing Rivers knew, Allen was on the ground grabbing his eye.
“It was a post pass and cut,’’ Rivers said. “Perk was supposed to hand off low and Perk was going to fake it and go high. Unfortunately, he did it too late.
“You couldn’t see it, then all of a sudden he’s laying down. Then you saw the blood and you’re saying, ‘Oh no, I don’t think he’s faking.’ ’’
Though he was down for a while, Allen got up on his own power. He suffered a cut above his left eye that required five stitches at New England Baptist Hospital.
“He got hit pretty hard in the head and went down,’’ Rivers said. “I’m sure he had a buzz or something.’’
The Celtics made it through the preseason without any serious injuries to their starters, though Brian Scalabrine (ankle), Tony Allen (ankle), and Bill Walker (knee) will be unavailable for Tuesday’s season opener against the Cavaliers.
Rivers doubts that yesterday’s mishap will keep Allen out, but he said, “That’s the one that hurts because you don’t expect those to come at that time.’’
“He took a hard elbow,’’ said Rasheed Wallace. “It was unintentional, during a drill. But he took a hard elbow from Perk. I thought it was clean cut, because it wasn’t bleeding at first. After a while, that’s when it started coming.
“Now we know he’s a bleeder.’’
Yesterday, with the decibel levels getting out of control, Rivers decided to dial it down a bit, declaring a 30-minute window of silence.
“There was too much of it,’’ Rivers said. “I just told everybody today that they were too loud. So I said we’re going to have a non-talk practice for a half-hour.
“They were saying it’s a communist practice now. They weren’t happy that they couldn’t talk at all. The practice got quiet.’’
Wallace, probably No. 2 on the Most Talkative list behind Kevin Garnett, said Rivers had a point.
“Doc feels as though once we get to talking smack to each other here in practice that we lose our focus,’’ Wallace said. “The intensity’s there, but we lose the focus. Which on some plays he’s right, but I think that’s just the character of some of the guys here in the gym.
“But hey, if that’s what Doc wants, then we’ve got to try to do that. We’ve just got to talk a little more quietly.’’
Rivers said it’s a good problem to have.
“This is a very verbal team,’’ he said, “which is a good thing actually. We just want to make sure we keep them under control.’’
Julian Benbow can be reached at jbenbow@globe.com. 
