The inevitable nostalgia that comes with leaving a place that has been the epicenter of his professional life for the past nine years finally overtook former Celtics coach Doc Rivers on Tuesday.

Rivers, who was released from his Celtics contract so he could ink a three-year, $21 million deal to coach the Los Angeles Clippers, was on the phone from the airport in Orlando, Fla., where his family makes their home. He was about to board a flight to Los Angeles, his new NBA address, and he couldn't help but take one last look behind at the place where he won his first championship and established himself as one of the league's most coveted coaches.

"I always knew when I took the job with Boston that I would love the Celtics," said Rivers, in his first public comments since he entered negotiations with the Clippers. "I knew I would love the tradition and the players. But I had no idea how much I would fall in love with the city and the people in it. Honestly, I get emotional thinking about it. I will cherish every single moment I had in Boston."

He knows what his sudden detractors, who feel betrayed by his actions, are thinking: If he loved it so much, then why did he leave?

"It was just time," Rivers answered. "I really don't think it would be fair to get into all of that right now. I made a decision to talk with all of the Boston media following my press conference with the Clippers [on Wednesday], and I will honor that.

"I'll explain it to everyone then. But to say I was dying to get out of Boston, dying to leave the Celtics is just wrong. That's not how it was. That's not how I felt."

Rivers said the brethren of professional coaches who became his sounding boards and confidants during his Boston tenure was one of the unique perks of his job. He developed strong friendships with Patriots coach Bill Belichick, former Red Sox manager Terry Francona and current Bruins coach Claude Julien, each of whom won championships while Rivers was there. It was one of the many common bonds the men shared. They discussed, among other things, the passionate (and sometimes volatile) fan base, whose knowledge, Rivers said, was indisputable.

"The people of Boston know their sports, and they care," Rivers said. "None of us took that for granted. We all understood how rare and special that is."

Doc Rivers became tight with the coach who shared the TD Garden with him, the Bruins' Claude Julien. AP Photo/Michael Dwyer

Francona, who now manages in Cleveland, was one of the first to text Rivers when news of his decision to sign with Los Angeles was reported.

"He told me, 'I don't know, I'm not sure about how I feel about rooting for the Clippers,'" Doc said. "I told him, 'Hey, I understand. I've been wearing a Cleveland Indians hat around, and I've been getting a lot of crap for it.'"

Rivers said one of the more surprising and enduring relationships he developed was with Julien. The oft-maligned hockey coach just had his team's run at the Stanley Cup come to a heartbreaking finish, as the Bruins gave up two goals in 17 seconds of the third period to allow the Chicago Blackhawks to clinch the championship on Boston's home ice.

"I was on the phone with the Clippers last night talking through my deal," Rivers said, "and one of them asked me, 'So, do you feel like everything is in line?'

"I started shouting, 'No, no!' They said to me, 'Doc, what is it? What's wrong?'

"It wasn't them. It was that second goal [the game winner by Chicago's Dave Bolland]. I couldn't believe what I was watching. I felt so bad for Claude."

Rivers said he developed a habit through the years that, if something was on his mind, he'd wander down the hall of the TD Garden into Julien's office.

"We had a lot of great conversations," Rivers said. "I always told him, 'Claude, it's too bad about this feud between the Bruins and the Celtics, because you and I have a great time.' The players all got along too. I never understood where that whole conflict came from."

He knows there are some who will never forgive him for walking away from the Celtics. He realizes they will take it personally, no matter what he says Wednesday afternoon. But he believes the parting was best for all parties -- the Clippers, the Celtics (who received an unprotected 2015 first-round pick as compensation) and for him.

"I'm going to Los Angeles," said the former coach of the Boston Celtics. "Weird. Hard to believe. Next year, I can watch the Stanley Cup final at five o'clock.

"Gotta get used to that."

So does Boston.