DETROIT — The Celtics were credited with 19 assists in Thursday night’s win over the Thunder in Oklahoma City, but perhaps the Red Sox should be credited with one, as well.

It’s fairly easy to draw a straight line from the Sox to Brad Stevens’ halftime message and the turnaround that led the Celts from 16 down at the break to a 101-95 win.

Let’s first travel back to Thursday morning when Stevens was asked about the Olde Towne Team.

“They just continue to have this unbelievable mentality,” the coach gushed. “I haven’t watched every World Series for the past 50 years, but at the same time I can’t imagine any team looks like they’re having more fun than the Red Sox. And I think you can see that in their play, how together they are, how many smiles you see. Like, it’s just a fun team.”

The Celtics, meanwhile, were nothing approaching that as they stumbled to a 50-34 halftime deficit on OKC, shooting 31.8 percent from the floor. It’s hard to have any joie de vivre when you’re taking an 0-for-11 collar on 3-pointers.

Stevens essentially told them to keep playing hard, but to, you know, lighten up and be a little more Sox-like.

“Honestly, guys were frustrated,” said Jayson Tatum, who kept the C’s in the building with 13 of his 24 points in the opening half. “We weren’t hitting shots, and Brad came in the locker room and told us we were getting good shots and we were playing good ‘D’ for the most part. But we were just too tense. Nobody was smiling, nobody was having any fun. That was the difference in the second half. We just had to regroup. It’s basketball at the end of the day. We all get paid a lot of money to do what we love, and we just had to get back to having fun.”

Marcus Morris certainly enjoyed himself, hitting 4-of-5 treys and scoring 19 of his 21 points in the latter half. He got Stevens’ message.

“He kind of felt that we were a little tense,” Morris said. “We were praying that we were making the shots. Miss or make, we’d rather keep moving forward, keep moving the ball and keep being ourselves.”

The key now is for the Celtics to carry that good feeling over and earn their first winning streak of the season after a W-L-W-L-W start. To get there, they’ll have to get by early season surprise Detroit (4-0) here tonight.

And they’ll have to shake off the yoke of expectation that seems to have weighed the Celts down rather than inspire them to live up to their billing.

Kyrie Irving thinks the Celts may have survived the head game and are now ready to move on.

“Yeah, for sure,” he said. “We all have great relationships outside of it, but I think that — coming off the summertime, having a short preseason, starting off the season of being ‘that team’ so to speak — it could hit your ego a little bit.

“When you come to the realization that it’s not going to be exactly what you thought it was going to be coming into the season, it’s not last year, it’s totally different team. We have the same players, but it’s a totally different dynamic. Guys have gotten better, some guys are filling better roles in different areas, just the timing of the game, and literally this is a challenge for all of us to just really be supportive. No matter what, we have to stay the course.

“That is something that’s scary to think about as professionals, that we still have to be better as individuals and better as a team, but it makes this year, going through it, a lot more special to see the growth that we can have, of getting better every single day as a team.”

Twitter: @SteveBHoop