Boston Celtics coach Doc Rivers isn't done chasing titles.

President of basketball operations Danny Ainge announced Friday the team and Rivers have agreed to a five-year contract extension.

The value of the contract is believed to be more than $6 million per year, a source told ESPN The Magazine's Ric Bucher on Thursday night.

Told Thursday that the sides were talking about a new deal, players were happy.

"If we're moving forward next year and trying to win a championship, he's one of the main pieces," Paul Pierce said.

Rivers, who completed his seventh season in Boston this year, and the Celtics won a championship in 2008 and came up just short in 2010. The lost in the conference semifinals to the Heat in five games this season.