McLaren team principal Andreas Seidl has warned his drivers must have "full focus" on F1 despite the allure of the Indianapolis 500 and the Le Mans 24 Hours.
The two races make up two legs of motorsport's triple crown, with the Monaco Grand Prix completing the trio of great races.
Fernando Alonso missed the 2017 Monaco race to compete in the Indy 500 with McLaren's backing, whilst entering twice with the team's associated IndyCar team Arrow McLaren SP.
After Lando Norris signed a contract extension ahead of the race in Monaco, Seidl was asked if this included the option to race in another series with McLaren, to which he replied: "That’s obviously a question you will have to check with Zak. He’s in charge of all the other projects."
But pertinently, he added: "My focus is on Formula 1. I also think it’s important for both Daniel [Ricciardo] and Lando to have full focus at the moment on Formula 1. This task is big enough.
"Once we have achieved our goals as a team then I think it’s the right time to also discuss other projects within McLaren Racing."
Speaking after the signing of his new multi-year deal, Norris insisted the Indy 500 was on his horizon but ruled out any attempts at the race in the near future.
"It’s definitely something I would still love to do at some point in my career," said Norris. "It’s not going to be this year or next year.
"This year, with Formula 1 with Covid and everything, you’re just not really capable of doing that and next year with the new rules, you want to be spending the time with the team and focusing on one thing.
“If you’re not, then you’re not doing a good enough job and you’re not doing everything you can to maximise your one objective."