Bernie Ecclestone has joined Sir Jackie Stewart in tipping Michael Schumacher to return to retirement at the end of 2010.
Half-way through the great 41-year-old's mediocre return to F1 with Mercedes this year, former triple world champion Stewart said this week he thinks Schumacher "will stop after this season".
And F1 chief executive Ecclestone added: "If Schumacher doesn't perform I doubt whether he will want to stay."
However, the Briton also told the London based business publication City AM that Schumacher is "obviously fit, motivated and talented but the car hasn't been up to him".
On other matters, Ecclestone tips Sebastian Vettel to win the championship, while his team Red Bull "deserve to win".
"Red Bull bought a team (Jaguar) that was no good, it's not like they bought Ferrari," he added.
The 79-year-old also hailed Vettel's teammate Mark Webber, the only driver so far in 2010 to have won more than two races.
"I would never have believed it at the beginning of this year if somebody had said to me he is going to do this," said Ecclestone.