Formula 1 legend Sir Jackie Stewart expressed his concern over fellow Brit Lewis Hamilton, saying he may have got carried away with success.
Stewart, who is also a three-time World Champion, said that Hamilton seems distracted in the fight for his fourth World Championship with his Mercedes team-mate Nico Rosberg, who regained the lead on the Championship table after the Singapore Grand Prix.
"Maybe you can bottom out," he told The Daily Mail.
"That can happen through consistent success because when you have consistent success everything can seem so easy.
"Suddenly things can go less well – you overdrive, you are not on the ball, or you live a life that distracts you in one way or another.
"If you are at the top in any line of work, you can get carried away with success. You think you can get away with things. Then someone else comes along and drives better or more consistently."
With the Malaysian Grand Prix up next, Hamilton has to close down an eight-point deficit with six races left if he is to claim his fourth title.