NBA Finals Game 5 updates

BOSTON — Joe Mazzulla hasn’t smiled much lately.

The 35-year-old Boston Celtics coach is nothing if not serious in these NBA Finals, like a much younger version of Gregg Popovich without the championship resume (not yet, anyway). He answers reporters’ questions with insight and candor but typically does so with an extraordinary amount of stoicism. Doc Rivers, in other words, he is not. And you’ll certainly never mistake him for Mike Brown.

So to hear Jayson Tatum share Mazzulla’s pre-Game 5 message Sunday, when the Celtics forward tried to explain why Boston looked so disheveled in that Game 4 debacle of a defeat in Dallas (122-84), was to marvel at the incongruity of it all.

“Joe did a great job today of reminding us that it’s OK to smile during wars,” Tatum said. “It’s OK to have fun during high-pressure moments. We would love to win tomorrow, more than anything. But if it doesn’t happen, it’s not the end of the world. We have more opportunities. So just setting that (mindset) of ‘Don’t surrender to that idea that we have to win tomorrow.’ We would love to, absolutely. But Game 5 is the biggest game of the season because it’s the next game on the schedule. So (it’s) going with that mindset and just have fun. That’s really what we talked about today. Get back to having fun and being a team and how special we are and the team that got us here.”

It’s a nuanced and counterintuitive motivational approach, one that will be very interesting to revisit after the next game. In the meantime, there’s this bit of breaking news that took place after Mazzulla held a news conference of his own: He cracked a smile when, during a brief interaction on the TD Garden floor, I shared this incredible clip of an MMA fight from the night before.

Mazzulla’s affinity for mixed martial arts is well-chronicled, as he has trained for much of his life and sees all sorts of parallels between the octagon and the hardwood. As our Jay King wrote last year, Mazzulla made it a priority to return to jiu-jitsu training immediately after he was named Boston’s interim coach last season. Before Game 3 Wednesday, Mazzulla discussed his propensity for showing players clips of MMA fights while preaching the importance of remaining focused until the very end.

“There’s a lot of them (that I show),” Mazzulla said then when asked about his MMA motivational technique. “Usually every single fight. But I think it was (UFC) 302. The guy gets hit in the nuts, complains to the ref and complains to the referee and gets distracted, and then he gets choked out the next round. So he lost his focus. You see (the fighter) gets hit in the nuts, looks at the referee, knocks the guy out five seconds later.

“So it’s the approach to what happens to you and how you handle it. The closer you think you are to beating someone, the closer you are to getting your ass kicked.”

That’s exactly what happened to the Celtics in Game 4. But they’re back in Boston now, where there will be 19,000 or so smiling faces if Mazzulla’s message inspires his squad to finish the job in Game 5 and give the Celtics what would be a league-leading 18th title.