Jenson Button needs to cope better with the pressure of leading the standings if the Briton wants to secure a first Formula One title, last year's runner-up Felipe Massa has told a British newspaper.
The Ferrari driver, recovering from life-threatening head injuries suffered in Hungary in July, told the Guardian in an interview published today that he was backing Button's Brawn team mate and Brazilian compatriot Rubens Barrichello.
Barrichello, a friend of Massa, is 16 points adrift of Button with five races remaining, but the championship leader has taken only 11 points in his last five races after winning six of the first seven.
Massa pointed out that he had been six points behind McLaren's Lewis Hamilton going into the final race last year and still almost won the title.
"That was one race, Rubens has five races to close 16 points. It's a big possibility but it depends on Jenson. If Jenson carries on in this bad way it will help Rubens a lot," he said.
"In my opinion, Jenson has gone down because of the pressure. It's the only reason.
"In the earlier races, he was almost half a second (a lap) quicker than some teams. You win the race easy and there is not so much pressure. But now we have races where things are more difficult," Massa said.
"So for me the pressure has had a big impact on his mind - and he needs to deal with it better. If he does not cope with the pressure he will not win the championship."
Massa, interviewed in his Sao Paulo apartment before undergoing cosmetic surgery on Monday, is not due to return until next season. He said he felt his accident happened for a reason and would make him stronger.
"Everything in life has a meaning. If something bad happens it's because you need to learn, to grow," he said.
"My life was once very difficult. When you think of the position I used to be in and what I had to do to arrive where I am now in my professional career. It was very difficult to reach this point.
"I had many races in the various categories where I knew if I did not win then I would not get to race in the next race because I did not have the money. So a lot happened that helped me become stronger," he added.
"I think there is a reason for this accident. At the moment I don't quite know what it is."
Massa said he was fortunate not to have been blinded or killed by the bouncing spring shed by Barrichello's car in qualifying at the Hungaroring and added that he would discuss possible ways of improving safety when he returned.
"For me, the worst thing that happened was not being able to race," he said. "If you can't drive that's terrible.
"My wife has already asked me, at least 10 times, 'Are you sure you don't feel any doubts or worries?' Always, I say, 'No - because this is what I like to do.' If I don't drive then I am not the same person."