Button buckling under title pressure - Massa

Jenson Button is buckling under the pressure of his bid for the 2009 world championship, according to the runner-up of last year's title fight.

Felipe Massa is currently recovering from head injuries sustained in a qualifying crash in Hungary in late July, but he has followed the progress of the intervening races from his Sao Paulo home.

With Brawn driver Button's points lead shrinking amid a run of disappointing form in the wake of his meteoric start to the season, Ferrari's Massa believes the Briton is struggling to deal with pressure.

"At the start of the season everything was nice, everything was easy (for Button).

"But now we have races where things are more difficult. 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," added Massa.

Having lost out to Lewis Hamilton by one point following a thrilling finale in Brazil last year, Massa now hopes a fellow Paulista is in a similar position to overtake the title favourite at the looming end of 2009.

"Look at me -- I came to Brazil six points behind (Hamilton) and I almost won the championship. Rubens (Barrichello) has five races to close 16 points. It's a big possibility," Massa told Britain's Guardian newspaper.

"But it depends on Jenson. If Jenson carries on in this bad way it will help Rubens a lot. In my opinion, Jenson has gone down because of the pressure. It's the only reason."

Massa contrasts Button's run of success until June's British Grand Prix to the pressure he subsequently faced in the form of the challenges by Red Bull and his teammate.

"In the earlier races he was almost half a second quicker than some teams. You win the race easy and there is not so much pressure. That's different to fighting hard for the championship. Now he has a different kind of pressure," he said.