The Celtics begin their NBA bubble playoff run on Monday night against the 76ers, and while everything looks differently, there is one thing that will never change for New England sports teams. Regardless of if teams are at home, on the road or playing in a Disney World bubble, the teams always have each other's backs.

Time and time again, this has proved true for Bill Belichick and Brad Stevens. Despite coaching in different leagues, the two have a relationship built on mutual respect, and ahead of the Celtics series, both Stevens said Belichick took the time to address his players.

"I think he is obviously one of the best coaches in any sports of all time and renowned as one of the best preparers of all-time," Stevens said in his media availability before tipoff, according to the Boston Sports Journal's Brian Robb.

Around the same time, Belichick appeared on his first WEEI Patriots Monday of the season and returned the favor.

"We have a great relationship with Coach Stevens here. We have several people who have worked with him," Belichick said. "Josh [McDaniels] is close with him. I'm close with him."

The relationship has only been strengthened over the years, with Stevens attending Patriots training camp in years past, and despite coaching in different sports, there is something to be said at competing at the highest level. In that, both Stevens and Belichick understand, even in atypical seasons.

"Playoff basketball, playoff football, it's a little bit different," Belichick said. "I don't know anything about basketball, but I know a little bit about competition and trying to perform well at the most critical time of the year, which is what they're entering."

This is true in the reverse, as well. Belichick said Stevens spoke to Patriots players this spring, and while this is nothing new, it is especially valuable in this current moment where so much surrounding the respective games looks different.

"We were starting our season, and they were preparing to go back and finish theirs, so it was quite different, but [he was] kind of talking about managing time and dealing with some of the challenges of being a professional athlete or a professional football team and things that were going on around us,"

Belichick said. "He's spoken to our guys several times, and he's great. He does a great job. He did a great job the night that he spoke at my foundation event. So anything I could ever do to help him or help them, I'd do whatever I could."

The respect doesn't stop at the head coaches, either. During a typical Celtics playoff run, if you took a glance at the courtside seats, there is no doubt that you would see at least on Patriots player -- if not a dozen. And they always get a warm welcome.

"If the Celtics were playing at the Garden, you know as well as I do, in the playoffs, we could have a team meeting at halftime. We'd have 25 guys there," Belichick said. "We have a great relationship with them."

The Celtics kickoff their series against the 76ers Monday night, and you can listen to all of Belichick's interview below.