Boston Celtics shooting guard Avery Bradley will undergo season-ending shoulder surgery on Friday, Doc Rivers told reporters at the team's practice Friday morning.

Bradley's shoulder popped out of its sockets three times in the postseason. After the most recent dislocation in Game 3 of the Eastern Conference Semifinals, doctors examined Bradley and decided he should not continue to play because of the chances the injury might get worse.

With Bradley out, Ray Allen becomes the Celtics' starter. Allen has struggled to find his outside shot as he deals with bone spurs in his ankle, hitting just 26 percent of his threes in the Philadelphia 76ers series.

Bradley's absence hurts against the athletic Sixers, but it could be lethal if the Celtics advance to meet the Miami Heat and Dwyane Wade.

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