Boston Celtics second-year shooting guard Avery Bradley needs surgery on his ailing left shoulder and likely will miss the remainder of the postseason, team president of basketball operations Danny Ainge acknowledged Thursday.

"We'll probably find out more here in the next few hours, but it's looking that way," Ainge said during his weekly interview on Boston sports radio station WEEI. "I think these reports are accurate -- at least the reports I've read. Someone said it was a 90 percent chance that he's done for the season, and it's looking that way."

The surgery is needed to repair small tears that have compromised the structure of his left shoulder, according to a league source.

Bradley has endured a number of dislocations during the 2011-12 season, including three in the postseason. After the shoulder came out in a Game 4 loss in Philadelphia in the Eastern Conference semifinals, doctors determined it was too risky to put him back on the court with the potential for a more serious injury, according to the source. Bradley has missed Games 5 and 6. The Celtics face the Sixers in a pivotal Game 7 on Saturday night at TD Garden.

With surgery unavoidable, Bradley is expected to undergo the procedure as soon as the team determines he's able. According to the source, Bradley is looking at a four-month recovery process, but the hope is he will be ready in time for training camp in October.

Pressed on what the summer would entail for Bradley, Ainge said, "Avery needs surgery. So he should have a summer full of rehab, and should be ready to go next year."

Bradley, a first-round pick (19th overall) in the 2010 draft, will miss his third consecutive summer league. After being drafted by Boston, he underwent ankle surgery related to a draft workout that likely caused him to slide late in the first round. He missed both summer league and most of training camp that year. This past offseason, the lockout wiped out summer ball and shortened training camp.

Despite all of that missed activity, Bradley emerged as a key member of the Celtics' rotation this season, taking over the starting shooting guard role when Ray Allen battled his own ankle injury late in the regular season.

Bradley's tireless on-the-ball defense has drawn notice across the league, and he earned a couple of coaches' votes for the NBA's All-Defensive teams (including one first-team vote).

According to the source, Bradley is despondent over not being able to get back on the court and help his team.

After Wednesday's Game 6 loss, Celtics coach Doc Rivers suggested the team couldn't lament not having Bradley on the floor.

"Listen, it's what we have, you know what I mean?" Rivers said. "Clearly, Avery's a great defender, but he's not out there, so I can't worry about it. I really can't. I understand what you're saying -- their penetration, their (isolations) without Avery on the floor -- clearly, they went to a lot of isos and they were picking who they wanted. But that's what I would do. You can't blame them for doing it."

Rivers had a sense of humor about the situation.

"(Sixers coach) Doug (Collins) and I are close. I'm going to give him a call and say, 'Listen, none of that.' That would be terrific," said Rivers, joking about stopping the isolations against susceptible defenders. "Listen, we just have to do a better job of covering for guys who may not be able to keep some of those in front of us. I didn't think we covered for each other very well. Having said that, they scored 82 points, so that's not a lot."