WALTHAM, Mass. -- Celtics second-year shooting guard Avery Bradley will undergo surgery Friday to repair small tears in his left shoulder and miss the remainder of the postseason.

Celtics coach Doc Rivers said the surgery will be performed by team doctor Brian McKeon.

"Avery Bradley is having surgery today, so he's out for the playoffs," Rivers announced at the beginning of his pre-practice news conference on Friday at the team's practice facility at HealthPoint.

"It's disappointing," Rivers said of losing Bradley. "Obviously when a player goes down that's disappointing, especially on what Avery has given us this year. His growth this year has been terrific, and it's been great, and he's become a very valuable piece to our basketball team."

A league source told ESPNBoston.com on Thursday that Bradley is looking at a four-month rehab and the team hopes he will be able to participate in training camp.

Rivers acknowledged the weight of losing Bradley, particularly on the defensive end.

"Avery's a big blow, yeah, there's no doubt," said Rivers. "If I'm the other guys on any other team, and the fact that I don't have to play against Avery Bradley, I would sleep a little better. No one wants to play against Avery. Our guys don't want to play against him in practice. He's a pain in the [butt] defensively. That's what he does."