Jacques Villeneuve thinks McLaren will have learned "a lesson" by failing to qualify for the Indy 500.
With a full team entry for the first time, McLaren ran Fernando Alonso in 2019 but the car was not fast enough even for the top 30.
"I am sure this will be a lesson for everyone," Villeneuve, who won the Indy 500 in 1995 prior to switching to F1, told Spain's Marca.
"This is probably the most difficult competition and they wanted to do it alone," said the 1997 world champion.
Many believe McLaren, which is now run by Zak Brown, faltered at Indy because its main focus is on Formula 1.
"You have to do it properly, and it's difficult to prepare for something like that with one race per year," Villeneuve said.
In any case, Villeneuve supports Alonso's push to win the 'triple crown', with the Spaniard having won Le Mans last year.
"He knows he cannot beat all the records in Formula 1, so he can try to win a little bit of everything instead," said the Canadian.
As for F1 this year, Villeneuve says Mercedes' utter dominance so far is not good for the sport.
"It's terrible for F1," he said, "because it's been going on for such a long time.
"It's basically impossible for Mercedes to be beaten with these current regulations," Villeneuve added.
