McLaren CEO Zak Brown says he is "confident" the plan to create a separate team for Fernando Alonso's 2019 Indianapolis 500 run won't disrupt their Formula 1 operation.

Despite opting against a full-time return to IndyCar next season, the British outfit will head back to Indy for a one-off attempt of the famous oval race, the final hurdle in Alonso's path to motorsport's Triple Crown.

McLaren is expected to be a standalone entry second time around after Michael Andretti deleted a tweet hinting at another tie-up with his Andretti Autosport team, Brown though is unconcerned.

"It's a whole separate racing team that will be created," he said on Sunday in Brazil.

"We are a large racing team with lots of resources and I'm extremely confident or we would not have entered, that we can give maximum effort toward our F1 and this Indy 500 effort without one compromising the other."

The American also revealed such an entry was always an ambition with time the main hurdle on the first occasion.

"We've always had a desire to go as 'McLaren Racing', the last time we did it on such short notice it would have been impossible," Brown claimed.

"I think it was six weeks between announcing and racing and you can't build a race team up that quickly, so that was one of the things shareholders and ourselves wanted to do and go as McLaren Racing.

"That's why we made the announcement [now] to give us sufficient time to bring those resources and people in to have our own team."