Australian centre Aron Baynes' move to NBA heavyweights Boston has been confirmed.
The 30-year-old has officially been unveiled by last season's Eastern Conference finalists, after two years in Detroit.
Baynes decided to walk away from the $US6.5 million ($A8.6 million) player option he had with the Pistons, becoming an unrestricted free agent and testing the NBA market.
Rio Olympian Baynes, who won the NBA championship with San Antonio in 2014, averaged five points and more than four rebounds from 15.5 minutes a game in 2016-17.
"I think being in the NBA, everyone always wants to play more," he said at his introductory press conference in Boston.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"I think if you don't want to play more then you're not in the right spot, so I'm excited for the opportunity and hopefully I can go out there and own some minutes."
Baynes is looking forward to "being a piece that brings that puzzle together" in Boston and will have a familiar face in Marcus Morris to assist his transition.
"I'm excited to play with Marcus again," Baynes said.
"The guy is a professional both on and off the court. He's got a great work ethic and I love the way he plays.
"We look forward to bringing some extra toughness combined with us."
Baynes will play with the Celtics' big off-season recruit Gordon Hayward, who has starred for Utah over past seasons alongside Australians Joe Ingles and Dante Exum.
The Celtics, who lost to LeBron James' Cleveland in the playoffs, took highly-rated youngster Jayson Tatum at No.3 in the draft.
