Motorcycling world champion Valentino Rossi has the talent to drive in Formula One, Rubens Barrichello said on Friday.
Rossi impressed during a secret Ferrari test this year and Barrichello believes, with enough mileage under his belt, he could switch from two wheels to four.
"If he can do in a car what he does on a bike it would be fantastic. He would beat all of us."
The Italian press has speculated that Rossi could have a chance if champions Ferrari have to run three cars next year to make up the numbers on a depleted starting grid.
On the eve of the last race in Monza, Ferrari boss Jean Todt was quoted as saying: "If Rossi wants to race in Formula One, it is entirely up to him."
Seven-times F1 world champion Michael Schumacher praised Rossi as a "natural" after the Italian drove the Ferrari at the team's Fiorano test track in April.
CAUTIOUS NOTE
Barrichello, however, sounded a note of caution for Rossi.
"I was there the day Valentino (tested) the car and he ran very well," he said. "Obviously, for him to race I think he will need more than just the month of December to test.
"He will need a lot of testing to be able to get reasonable times out of the car."
Meanwhile, former world champion Jacques Villeneuve also backed Rossi.
"He is so quick on a motorbike, there's no reason for him to be slow in a car," said Villeneuve, who will make his race return after a year out on Sunday.
"He's a great driver. I'm sure with enough testing he would be up to speed. The main difficulty would be physical because F1 hurts.
"If you haven't been in a car and you have been on a motorbike, the first winter won't be enough physically. You just need a lot of mileage."