DALLAS — It was, by most accounts, a perfect situation.

Cooper Flagg was beginning his NBA career on the contending Dallas Mavericks, with league champions next to him on the court and in the locker room, looking to continue a winning culture that only a year ago resulted in a trip to the NBA Finals.

One month in, and the picture-perfect setting has been shattered. Injuries, most notably to star forward Anthony Davis, have hit the Mavericks hard as they dropped to the bottom of the league, with a 5-14 record after dropping Monday’s game to the Miami Heat.

As a result, the Newport native hasn’t just had to learn how to compete against the world’s best players on the sport’s biggest stage. He’s had to learn something even more foreign to him.

He’s had to learn how to handle losing.

“That’s one of the biggest changes, I think,” Flagg said after Friday’s game against New Orleans. “I haven’t lost this much before. But it’s a big learning curve.”

It’s not that Flagg has never been challenged. He’s been tested since his middle school days at the highest levels of competition available to him, and has always flourished. At Nokomis Regional High School in Newport, he was the best. At Montverde Academy in Florida, the best. At Duke, the best.

And because he’s been so good, he’s never been on teams that have failed. His combined record in high school and college was 112 wins and eight losses. He won a state championship in Maine, a national championship in Florida and brought Duke to the Final Four.

Now, he finds himself on a snakebit Mavericks team that has struggled to turn spurts of good play into victories. Dallas is a woeful 4-10 in games in which the score is within five points in the final five minutes of play.

It’s led to some desperation in the Dallas locker room, and caused the hyper-competitive Flagg, who’s played in all but one of those games, to have to deal with a level of frustration he’s never previously encountered.

“Obviously it’s different,” he said. “Every game, we’re feeling ‘Oh, we need a win, we need a win.’ It does feel like that a little bit. But I’m just trying to push that back, just be comfortable and just play free out there.”

Flagg’s play hasn’t been a problem. The expectations of being the first overall selection in June’s NBA draft haven’t fazed him; his 16.1 points per game lead the team among players who’ve played in at least half the games. He’s second among NBA rookies in scoring, and third in rebounds.

“His I.Q. is extremely high,” Dallas coach Jason Kidd said. “He can read the defense, he looks to make plays for his teammates. He doesn’t take shots just to take shots. He tries to get the best shot for his teammates and for himself.”

Kidd said Flagg has shown the ability to perform better in big moments, such as when he scored 21 of his 29 points in the second half to lead Dallas from a 15-point deficit to a 118-115 victory over New Orleans on Friday.

“He’s done that for us all season,” Kidd said. “The big rebounds, the big block, a big basket. In clutch, he’s not afraid of getting the ball. It seems like he’s been there before. … When everyone knows you’re coming to him, he’s delivered. For an 18-year-old, that’s pretty special.”

The adjustment of Flagg, the NBA’s youngest player, relating to players 10 to 15 years older than him hasn’t been an issue, either.

“He’s very chill, very goofy,” teammate Max Christie said. “He’s very mature, he’s very smart. … It’s not surprising, and it’s obviously good to see him out here have great chemistry with the guys, and jell a little bit, at such a young age.”

It’s the losing that’s given Flagg the toughest time. He acknowledged that the setbacks stick with him, and to help process them, he’s turned to some of those older players.

“That’s one of the biggest things I’ve learned from some of the older guys and the vets, about being even-keeled all the time,” he said. “(I’m) learning from a lot of vets and talking with them about how they dealt with it at some point in their careers. I’ve got to learn how to take the losses better and move on quickly.”

Kidd — a former star player and an NBA Hall of Famer — said he hasn’t had to remind his rookie to stay poised, even as the losses mount.

“He doesn’t press,” he said. “He continues to try to do the right things at all times, offensively and defensively, and that’s just something that’s in his DNA.”

Kidd added that learning how to handle losses is an inevitable lesson.

“He’s going to be in this league a long, long time, and I don’t know if he’s going to go undefeated,” Kidd said. “But (he needs to) just understand that losing is something where you can turn it to a positive.”

Losing also isn’t forever. Flagg sees that.

“It’s early. There are so many games in this league that we’ll play,” he said. “(I’m) not getting too high or too low on any possession or night or anything like that, but just trusting my work and all the hours.”