“We wanted him for five years and he wanted to stay for five years,” Ainge said. “I think Doc is the best coach in the league, so I think it’s great for us.”
Rivers indicated it was likely he would return to the Celtics after Wednesday’s season-ending loss to the Heat. “I’m leaning heavily [toward] coming back,” he said. “I haven’t made that decision, but I can tell you I probably will. I’ve kind of come to that over the last couple of weeks.”
Rivers has coached the Celtics for seven seasons, posting a regular-season record of 336-238 and a playoff mark of 46-34. He led the C’s to the 2008 NBA championship. If he serves out the length of the contract, Rivers will pass Tom Heinsohn for second on the list of longest-tenured coaches in franchise history behind only Red Auerbach , who coached for 16 seasons.
“He’s a great leader in the face of adversity,” Ainge said. “There’s nobody I’d rather have on my side more than Doc.”
Rivers decided after last season to come back for one more year. The two sides talked about a long-term deal, but the feeling was that it was too rushed and they agreed to resume talks in training camp. They let the issue be until mid-season when they talked some more and then essentially decided on a direction as the playoffs began. “He understood that it was important for me to know,” Ainge said.
With Kevin Garnett , Paul Pierce  and Rajon Rondo  under contract and Ray Allen  likely to exercise his player-option for next season, the Celtics will return the core of the team that Rivers has coached the last four seasons. Garnett and Allen will both be free agents after next season and the Celtics will likely undergo an overhaul, but Ainge said Rivers was committed to the long haul.
“He knows the circumstances of our team as well as anyone, the players, the ages the contracts, he gets it all,” Ainge said. “He wants to be part of this franchise and he wants to be working with us. We have a great relationship with owners, management and coaching that I think is unique.”