ORLANDO, Fla. -- The phone started ringing shortly after Doc Rivers landed in his native Orlando. The number was private, and the Celtics coach's normal reaction to a number he did not recognize was to let it go to voice mail.
"But for some reason,'' Rivers said Friday, "I picked it up.''
The voice on the other end was unmistakable.
"Hey Doc,'' Shaquille O'Neal said. "Can we talk?"
Rivers recoiled with surprise. It was the summer of 2010, and just two days earlier he had been discussing Shaq with Celtics boss Danny Ainge. The big man was a free agent, and Ainge was contemplating signing him. Rivers was skeptical at best.
"I don't know how healthy he'll be,'' Rivers told Ainge. "I don't know if he wants to play for us. I don't know if we need a guy with that big of a personality in our locker room.''
Shaq was aware of Rivers' reservations. He knew Doc was a Pat Riley disciple and stories of his conflicts with the Heat coach/general manager likely had made their way to Boston.
"I want to play for you,'' Shaq told Rivers. "I want to play for the Celtics. I want to help you win a title.''
Rivers, who had made inquiries about O'Neal from his previous teams and was less than enthused by some of those reports, wasn't buying the sentiment.
"Aw, c'mon, Shaq,'' Rivers said.
"I'm serious,'' the big man said. "I just want to win.''
Within half an hour, Shaq was sitting with Rivers in his Winter Park home. The coach rattled off his list of stipulations should O'Neal become a Celtic: no guarantee of a starting job, no guaranteed minutes, no superstar perks. And then Rivers went for the jugular.
"I told him, 'I'm willing to cut you on the spot if I think you are getting in the way of winning,'" Doc said.
The big man listened patiently, nodding his head with each ultimatum issued. When Rivers was done, O'Neal stuck out his hand and said, "I'll make it work. You have my word.''
Rivers took his hand and took the bait. He signed off on bringing the future Hall of Famer to Boston.
Shaq lasted only one season with the Celtics, cut down by an injured Achilles that robbed him of his mobility and his ability to make good on his promise to bring Boston another championship. But even after only one year, his respect for Rivers was so immense he mentioned him in his retirement news conference in the same breath as Phil Jackson, the man who was at the helm when Shaq won three straight titles with the Lakers.
"I mean it,'' O'Neal reiterated Friday afternoon, in a quiet moment after his celebrated news conference had finally ended. "Doc never stopped preaching team. He never wavered. And if you doubted he was serious about it, then just try and challenge him.''
Shaq admired the way Rivers held veterans and rookies accountable in the same manner. He watched with interest as Rivers preached "team'' in film sessions, never singling out players as he ran damaging footage of selfish moments, allowing the pictures to speak for themselves.
Rivers is a players' coach, an NBA veteran who experienced the same highs and lows as them. He wasn't a Hall of Fame-caliber talent, but he talks their language. He oozes credibility.
His first on-the-court encounter with O'Neal was in Shaq's rookie season,1992-93, when the Orlando Magic made a road trip to Madison Square Garden to play New York.
"I think I kidded him about this 1,000 times this year,'' Rivers said. "I was playing for the Knicks, and he had five fouls in the game. He came across, and we had the ball, and I set a cross screen and completely flopped. He got his sixth foul and was out of the game.
"He was furious. He told me all those years later that he was in the locker room telling guys, 'The next time I see that guy Rivers I'm going to mess him up.'"
In spite of suckering the rookie with the phantom foul, Rivers was immediately impressed with the young center's powerful game.
"People want to compare him to Wilt Chamberlain in terms of dominance and size,'' Rivers said, "but Shaq weighs about 75 pounds more than Wilt did.
"It's just so rare for someone that big to be that athletic and that coordinated. I really believe because of his size, people underestimated his athleticism.''
Neither the coach nor the player will ever know whether Shaq's presence could have tipped the scales toward a championship for Boston. In games that he played 21 minutes or more, the Celtics posted a record of 21-4. Point guard Rajon Rondo averaged more than 15 assists a game when Shaq was on the floor.
The problem was he couldn't stay healthy. A debilitating Achilles injury limited him to two postseason games, even as he kept imploring the team doctors to shoot him up with another cortisone shot.
"I don't think people realize all the stuff he tried to do to get on the floor,'' Rivers said. "It got to the point where the doctors had to say, 'No more. You can't play anymore.'
"It was a tough day. I remember him sitting in the bathroom close to tears. He was so disappointed. He really wanted to help us.
"I had grown to like and respect him so much, it was hard to watch. That's not any way a guy of his caliber should go out.''
The coach and the player shared an abbreviated journey that both of them have come to appreciate, in spite of the final results.
"For the first time in his life, someone asked Shaq to be a role player,'' Rivers said, "and he did it. He did everything we asked him to do. He was phenomenal.''
O'Neal retires having gathered four rings playing for six franchises and 12 coaches in 19 years. He had always touted Jackson as the best, yet now he's placed Rivers alongside Jackson.
"Obviously, when you hear something like that, it makes you feel great,'' Rivers said. "I don't see myself there. I only have one title. But it's nice to have that effect on a player.
"It's why we do this. You want to win and impact players you coach. It makes you feel like you are on the right path."
As he was winding down his umpteenth media interview, O'Neal began spouting what he referred to as the "Doc Rivers philosophy.''
"You have to be willing to sacrifice,'' Shaq said. "That's what the great Doc Rivers preaches.''
The player smiled. Hours later, when apprised of the comments, the coach beamed. It was only one season, but their connection was real -- and everlasting.
Doc Rivers is part of the Shaq-o-sphere now. It's a rarified -- and privileged -- honor. The Big Man never forgets, especially those who taught him how to win.
Jackie MacMullan, who has spent nearly 20 years as a beat writer and columnist in Boston, is a columnist for ESPNBoston.com.