BOSTON (AP) _ Danny Ainge finally has a coach of his own choosing.

The boss of the Boston Celtics hired Doc Rivers on Thursday to be the 16th coach in franchise history and the third since Ainge took over as team president less than a year ago.

``I have all the trust in Doc to turn the entire locker room over to him,'' Ainge said. ``I think it goes both ways: I believe in Doc and Doc believes in me. That's a great feeling.''

It's also a new feeling for Ainge, who clashed with former coach Jim O'Brien. O'Brien quit in January, citing philosophical differences, and has since been hired by the Philadelphia 76ers.

John Carroll, an assistant coach brought in by Rick Pitino, took over as interim coach and finished out the season. He was let go on Monday, a day after the Celtics were swept out of the playoffs by the Indiana Pacers.

``As soon as Jim O'Brien left, I started contemplating what we might do for our future,'' Ainge said. ``Doc was someone I thought of right away.''

Ainge went to Orlando on Monday to interview Rivers.

``Danny Ainge called me and asked me to coach the Boston Celtics,'' Rivers said. ``If you like basketball, I don't know how you could say no to that.''

Rivers spent 13 seasons with the Hawks, Clippers, Knicks and Spurs, playing on the 1986 Atlanta team that the Celtics defeated in the second round on their way to their last NBA title.

He retired as a player in 1996 and worked as a TV analyst before becoming the head coach in Orlando in 1999. In his first season, he was the NBA's coach of the year after leading a team with four undrafted starters to a .500 record.

Rivers went 171-168 in five seasons with Orlando before he was fired in November when the Magic opened the season with one win and 10 consecutive losses. He has been working for ABC as an analyst ever since, a job he will keep through the NBA Finals.

Rivers, 42, takes over the coaching reigns for the once-proud franchise that amassed a record 16 NBA titles. Two years after reaching the conference finals, the Celtics made the playoffs this year with a 36-46 record.

But the real problems were beneath the surface, starting a year ago when Ainge was hired in the middle of the playoffs to clean house.

Ainge, in a series of trades that turned over most of the roster, jettisoned star Antoine Walker and several O'Brien favorites who stood out for their hustle and defense.

Carroll lost 12 of his first 13 games but still was able to grab the last playoff berth in the East. But four quick losses later, he was gone, too.

``I know this isn't a job you walk into and you walk into the (NBA) finals. I know that fully,'' Rivers said. ``I wouldn't be here if it weren't for my relationship with Danny.''

Rivers said he wanted the team to run the floor more than it has in the past without becoming soft on defense. He said he wanted to get help for Paul Pierce, who was frustrated at the end of the season by his inability to do everything himself.

``When you lose games, you get down,'' Rivers said. ``I don't think he was down on himself _ he was down on losing.''

Rivers said he welcomed the challenge of coaching Ricky Davis, the talented but occasionally troublesome guard who has had trouble fitting in on four separate teams.

``Some of his judgments at times have not been great,'' Rivers said. ``But if I'm in a game I would rather have a guy (like Davis) who is capable of taking a game over.''

Four players _ Raef LaFrentz, Jiri Welsch, Kendrick Perkins and Walter McCarty _ sat in the front row at Rivers' news conference. After his opening remarks, Rivers turned to them and said, ``You'll find me with no agendas. I just want to win.

``However we find a way to do that, that's what we're going to do.''

They seemed receptive to the message.

``I think,'' McCarty said, ``it's the first move in, hopefully, the right direction.''