Oscar Piastri is back on the grand prix winning trail, suggesting that teammate Lando Norris's receding Formula One title hopes have freed him up to shoot for glory at McLaren.

Norris may remain the leading challenger to Red Bull's reigning champ Max Verstappen, but the Dutchman will wrap up a fourth successive title at the Las Vegas Grand Prix on Sunday should he defeat his pursuer.

And after his sterling work as a support act to Norris in recent weeks, Australian ace Piastri has revealed he has been given the green light by the team to go for success on his own terms without being under team instructions to help maximise Briton Norris's points-scoring opportunities.

Instead of individual success now, the British team is concentrating on winning the constructors' championship, as McLaren sit 36 points clear of Ferrari with three rounds left.

"There's still some, let's say, very specific scenarios where I might be needed to help out. But for the very large majority of situations, it's back to how it was," Piastri said in Las Vegas.

"The drivers' championship picture is very slim, and the constructors' championship is certainly not over for us.

"So it's a very specific few scenarios that maybe I'll still help out if that's what I'm asked to do, but I'm going into the weekend trying to win."

Piastri has already won twice this season, his maiden win in Hungary in July and in Azerbaijan in September, as he lies fourth in the overall standings with 262 points, behind Ferrari's Charles Leclerc (307), Norris (331) and Verstappen (393).

Norris also reporters that the team had always come first and that would not change.

"Everything we've done, we've just swapped a position," he said.

"It benefited me because I was in the fight for the championship and that's the game we also have to play, just as I've helped Oscar in a few occasions and helped him win in Baku. I did my job there."

Piastri has already earned plenty of kudos as the ideal team man after sacrificing the sprint race race win at the Brazilian Grand Prix.

But, naturally, he's happier not to be reined in by team orders.

"To be honest, I wasn't that disappointed with giving that up," he said.

"I knew I did the right thing in the sprint, and that's good for me. So I'm happy that we don't have to go into those kinds of things as much anymore.

"And obviously next year, I want to make sure that I'm not in a position, championship-wise, to be subject to that."

Last year, Piastri had a notable drive in Vegas, starting 18th on the grid before weaving his way through the field to finish in the points in 10th place.