The Philadelphia 76ers have fired head coach Jim O'Brien and replaced him with Maurice Cheeks. O'Brien lasted just one season in Philadelphia after being introduced as the head coach on April 21, 2004. He guided the 76ers to a 43-39 record and the seventh seed in the Eastern Conference playoffs. Philadelphia was ousted in the first round of the postseason by the defending champion Detroit Pistons. The 53-year-old O'Brien, a Philadelphia native, had spent the previous seven seasons in the Celtics' organization. He resigned as coach of Boston in late January of 2004 after several conflicts with Danny Ainge, the team's director of basketball operations. O'Brien took over in Boston for Rick Pitino on January 8, 2001 and compiled an overall head coaching mark of 139-119 with the Celtics. Cheeks was dismissed as head coach of the Portland Trail Blazers on March 2 after the club dropped 33 of its first 55 games this season.