For the first time all playoffs, the best player in a Celtics series won’t wear green and white.

Starting Thursday might, he’ll dance, perhaps dominate and definitely whine in Mavericks blue.

Luka Doncic is a top-three player in the world, playing at the peak of his expanding powers. He is Dallas’ driver and engine, a scheme-proof, matchup-resistant star.

Doncic scores at an elite level, passes as well as anyone and manipulates half-court defenses, sowing doubt and cracks he can exploit better than anyone on the planet.

As a fellow top-10 player, Jayson Tatum resides comfortably in the same starry neighborhood as Doncic. It’s just that Doncic lives at the end of the cul-de-sac, up on a hill with more cars in the driveway and a bigger pool out back.

Now, the Celtics shouldn’t care about the gap between Tatum and Doncic. Overall they boast superior talent and the better team. But Boston ought to be wary of the gap between Tatum and the next-best player in this series, and who that player is.

More to the point: will it be a Celtic or a Celtics villain?

If Kyrie Irving is the third-best player in the Finals, he will swing a series expected to end with Banner No. 18 for Boston into a tossup, and maybe in Dallas’ favor.

The Mavericks are coming off consecutive upsets of Oklahoma City and Minnesota because Irving and Doncic were brighter than the opposing stars. The Mavs didn’t win those series playing two-on-two – and the Finals won’t be a 2-on-2 test, either – but make no mistake: star power makes Dallas go.

No one else on its roster is scoring even 14 points per game in the playoffs. Just one, P.J. Washington, is averaging double figures. Together, Doncic and Irving scored or assisted on 74.3% of the Mavericks’ points this season, the highest percentage of any duo to reach the NBA Finals in the last 25 years, according to ESPN.

Both stars are elite scorers and playmakers, able to create shots from nothing for themselves and teammates. If Irving elevates above everyone else in the series, excluding Doncic and Tatum, he’ll take the rest of the Mavs with him.

Simply forcing the ball out of his hands with help or double-teams isn’t an option. Oklahoma City loaded up against Irving and Doncic in the second round, using full-court pressure and early rotations off Dallas’ role players in the half-court to guide the ball into less threatening hands. Eventually the Thunder broke under a barrage of open 3-pointers from Washington, Derrick Jones Jr. and Josh Green, who fed off their star teammates’ gravity and greatness.

After averaging an extra assist per game in that series, Irving’s regular-season scoring average jumped by almost two points in the next round against Minnesota’s staunch, top-ranked defense. Together with Doncic, he exploited the Timberwolves’ plan to limit 3-point attempts by guarding them one-on-one. Initially, Anthony Edwards defended Irving and Doncic faced Jaden McDaniels, an All-Defense second-teamer, while Rudy Gobert, the Defensive Player of the Year, loomed at the rim.

But Doncic’s master manipulation and Irving’s expert shot-making not only forced Minnesota to abandon its core defensive principles through two games, but cycle through as many as eight coverages in Game 3. Dallas won that night and eventually finished the Wolves off in Game 5, when Doncic and Irving became the first teammate duo in decades to score 35-plus in a conference finals game.

Two stars, one knockout punch.

Given Boston’s defensive versatility and long layoff heading into Thursday night, Coach Joe Mazzulla could be planning to unleash eight coverages in Game 1 alone. In their last meeting, the Celtics showed a willingness to blitz Doncic more than they had against other opponents. Boston blew out Dallas 138-110 on March 1; days before a reshuffled Mavs roster began to jell and built the NBA’s second-best record over the rest of the season.

Back to Irving.

If Boston can disrupt him enough, or tire its old pal out by hunting him on switches, Jaylen Brown should assert himself as the third-best player in this series. Brown, the Eastern Conference Finals MVP, is playing the best basketball of his life. He will face good but not great individual defense against Washington or Jones Jr. His defense on the other end will be paramount.

Brown was the most common matchup for Doncic in the regular-season meetings. Success against a future Hall of Famer is not holding him to fewer than 20, 25 or 30 points. It’s about leverage.

Brown and the Celtics must steer Doncic away from his preferred spots, and the ball from where Dallas wants it to go. The same holds for Irving, because there is no solution for either player.

Derrick White, Boston’s likely defensive answer for Irving, admitted as much Saturday.

“There’s really no stopping them. You just try to make it difficult for them,” White said. “They’re going to take tough shots, and they’re going to make tough shots. So just continuing to trust the game plan; trust that over 48 minutes what we’re doing is going to work.”

And that over seven games, you can slow Irving or outrace him in an all-time reunion with legacy stakes.