MIAMI — Andy Reid’s coaching tree is big and bountiful.

It has produced 10, and counting, NFL head coaches, who have won two Super Bowl crowns and 12 division titles, been to six conference championship games and made 19 playoff appearances.

A whopping six of Big Red’s coaching offspring — Doug Pederson (Eagles), John Harbaugh (Ravens), Sean McDermott (Bills), Ron Rivera (Panthers), Matt Nagy (Bears) and Pat Shurmur (Giants) — ran their own ships this season. Three of them — Pederson, Harbaugh and McDermott — had their teams in the playoffs along with Reid’s Chiefs.

McDermott, Harbaugh and Pederson have had a few weeks to get over their own disappointment over not making it to Super Bowl LIV. Sunday, they’ll all be rooting hard for their former boss to finally get the Lombardi Trophy monkey off his back when the Chiefs face the San Francisco 49ers.

It is the “but’’ that follows every discussion about Reid’s coaching success, which includes the seventh-most regular-season wins in NFL history and 14 playoff appearances, 10 division titles and seven conference championship-game appearances in 21 years as a head coach with the Eagles (14) and Chiefs (7).

“I’m going to be very excited" if the Chiefs beat the 49ers on Sunday, McDermott said last week. “I’ll probably get a little teary-eyed. I was just thinking the other day about what he’s been through. I’m pulling for him.’’

“The Harbaugh house will be rooting for the Chiefs hard,’’ said John Harbaugh, who spent nine years as an assistant under Reid before getting hired by the Ravens. “The Niners are really good and well-coached. Their defense is ridiculously talented. But I still think Andy, the wily veteran, will have some things up his sleeve. I’ll be anxious to see what they are.’’

That McDermott will be rooting so hard for Reid on Sunday tells you a lot about both men, given their complicated relationship.

In 2009, Reid gave McDermott, then 35 years old, his big coaching break when he promoted him from defensive backs coach to defensive coordinator. McDermott replaced legendary Jim Johnson, who was dying of cancer.

Two years later, Reid fired McDermott. But that’s not the end of the story, or the relationship. Even as he was letting him go, Reid was finding him new employment. He called Rivera and persuaded him to hire McDermott as his defensive lieutenant with the Panthers. McDermott coached there for six very successful years, which led to his getting the Buffalo head-coaching job in 2017.

Nevertheless, getting fired by the Eagles was a crushing blow at the time for a Philly kid who had been a football and wrestling standout at La Salle College High School and had steadily risen up the coaching ranks under Reid.

“It hurt,’’ McDermott conceded. “But Andy and I probably are closer because of it, Andy always told me it was something he had to do.

“Sometimes as a head coach, you’ve got to do things that aren’t easy to do. I think it was hard on him, and I know it was hard on me. I was young, so I didn’t realize it at the time. But it was the best thing for my career. That’s exactly what Andy told me at the time. He said it would be the best thing for my career. I didn’t understand it at the time, but I do now and have for a number of years.’’

McDermott had done a decent job as the Eagles’ defensive coordinator. But following a coaching giant like Johnson isn’t easy. Especially when you’re still in your mid-30s.

“Andy and I have had numerous conversations between then and now,’’ McDermott said. “And some of them have revolved around what happened there, why it happened, why it had to happen. Those are private conversations that I’ll keep between he and I. But I’m thankful that it worked out the way it did.

“That moment in Philadelphia and the conversations we’ve had about it have brought us closer together. I’ve learned so much from him. About coaching. About life.’’

McDermott said he got another valuable lesson from his former coach last week after the Chiefs defeated the Titans.

“It spoke volumes about Andy and the man he is when he was on the podium after they won,’’ he said. “It’s why he’s so loved in the football community. With all the hoopla going on about the Chiefs’ winning and going back to the Super Bowl for the first time in 50 years, the first thing he did was give credit to [head coach] Mike Vrabel and the Titans.

“He’s just done it the right way for so long. He doesn’t cut corners. When a guy can stand up there in that moment and keep his mind about him and display the kind of class that he displayed, it just said a lot about who he is.’’

Both Harbaugh and McDermott know how badly Reid wants to win Sunday. Pederson, who wasn’t available to comment for this story, won a Super Bowl in his second year with the Eagles. Harbaugh won one in his fifth year with the Ravens. Twenty-one years in, Reid still is trying to get that one win that will validate everything else he has accomplished.

He took the Eagles to the Super Bowl during the 2004 season, losing to Bill Belichick and the Patriots, 24-21. A decade and a half later, at the still reasonably young age of 61, he finally has made it back.

“I was talking to my wife the other night after they beat Tennessee" in the AFC Championship game, McDermott said. “2004 seems like such a long time ago. Who would have thought then that 16 years later would be the next time Andy would get another [Super Bowl] chance given how successful he’s been?

“You try and put yourself in his shoes. The journey he’s been on. You watch what he’s dealt with both on and off the field. He’s watched a couple of his assistants win the Super Bowl. He watched Ron and I get there with Carolina [in 2015].

“He watches other people off of his staff go and have success. I’m sure he felt good for all of us. But at the same time, I’m also sure that, deep down, he was thinking, ‘Well, why not me?’

“He called us all when we got there. We were there because of him. But as happy as he was for all of us, I’m sure he couldn’t wait to get back.’’

Now, at long last, he finally has gotten back. Harbaugh thinks Reid is a better coach now than he was during his 14 seasons with the Eagles because he has shed all the extracurricular responsibilities that he had in Philadelphia, where he also was the team’s executive vice president of football operations.

“I think not having all of those titles he had before in personnel has helped him,’’ Harbaugh said. “He’s told me that. He doesn’t have to deal with the day-to-day rigors of that aspect of the job. So he can just focus on what he loves to do, which is the offense and the play-calling and all of that.

“He knows how to attack people offensively. He delegates real well in the other phases and focuses real hard on attacking people. And man, it’s obviously paying off for him.’’