Luka Dončić isn’t himself, and no Mavericks adjustment will matter if he can’t

OKLAHOMA CITY — Over there, not too long ago, was Luka Dončić. Strutting with a 30-plus lead in an elimination game, snarling after a postseason game-winner. Visages still burned in our hippocampus. He was atop the world in that instant and knew it.

Now, here’s Luka Dončić, lingering on the floor after self-inflicted tumbles and leaning upon stanchions every chance he gets. Saying, “Who cares, we lost,” when asked about his 6-of-19 shooting night that yielded just 19 points, tied for his second-fewest ever in a playoff game. The man who averaged more points in the playoffs than anyone not named Michael Jordan now looks nothing like the player we have come to expect since he entered the league.

The Dallas Mavericks decisively lost Tuesday’s Western Conference semifinals opener to the Oklahoma City Thunder, with the 117-95 margin ballooning in the third quarter after Oklahoma City made necessary adjustments. Dallas has never won a Game 1 in coach Jason Kidd’s three-year tenure, even as the team’s gone on to win three of those four series. The fifth began Tuesday.

“I’ve got to be better (and) we’ve got to be better,” Dončić said after the loss. “We’re known for Game 1 struggles, but we’ve got to focus better.”

Dončić sprained his right knee in Game 3 of the team’s first-round series win over the LA Clippers and has been a recurring feature on the team’s injury report since. Before Game 5 of that series, he admitted he probably wouldn’t be playing if it had been the regular season. He said more recently that the ailment won’t be right until he rests this summer. Both answers were pried out of him in media sessions that began or concluded with him insisting he’s ready and able to play.

Oklahoma City is the antithesis of the team Dallas just beat. The Thunder are the league’s youngest team; the Clippers were the oldest. They use five players who thrive on the perimeter and a new unicorn, Chet Holmgren, still discovering his powers. In the opening minutes of the last series, Clippers center Ivica Zubac spent several possessions backing down his defender like bigs did before smartphones were invented. Holmgren doesn’t respect tradition like that.

“We have to adjust to the team we’re playing against,” Kyrie Irving said.

Dallas’ last stand came with a 12-4 run to begin the third quarter that cut the deficit to one. The Thunder reacted with Isaiah Joe replacing Josh Giddey, a shooter taking over for a bet-you-won’t-take-it presence. Dallas had the league’s best defense over the season’s final 20 games. Right before that, the team lost five out of six against several opponents that do play five shooters. The Mavericks benefit when there’s a weak link off which to cheat, and the Thunder removed that player from the game.

Once Joe made his entrance in the third quarter, the Thunder regained momentum and galloped away. Midway through the fourth quarter, with the Mavericks down 22, Kidd…