Mark Webber has admitted that he is suffering from a lack of motivation during the closing stages of his Formula 1 career.
The Red Bull driver, who will retire at the end of the current season, claims that he does not think of the sport in the same way he did when he was a rookie.
"I think towards the end of your career, you probably find little things that convince yourself that you're not enjoying it as much as you were," Webber told Sky Sports News.
"You're not 22 anymore and that's obvious; I'm 37 and I've done over 215 races at the end of the year, so the juice goes out of the tank a little bit.
"But at the end of the day, I'm still super-respectful of who I'm racing against and how I go about it. I'm still not blasé about competing at this level; I still respect it at this level. But there comes a time when you've got to get that decision right."
Webber will race for Porsche in next year's World Endurance Championship.