Is retirement on Michael's mind?

Yesterday's Belgian Grand Prix was the 13th anniversary of Schumacher's Grand Prix debut with Jordan at Spa in 1991 and he also won his first Grand Prix at the Belgian track with Benetton a year later. With both this year's titles now won and his brother still injured as the result of an Indianapolis shunt, might Schumacher even have decided to hang up his helmet with immediate effect?

Michael is contracted to Ferrari until the end of 2006 but is free to stop at any time. He has repeatedly said, however, that while he can work with the Ferrari team and enjoy his racing as much as he does, the motivation remains as strong as ever and he has no reason to retire.

But inevitably, all top sportsmen have to stop at some time and planning the right time to make an exit is often a most difficult task. In the last 31 years, only Jackie Stewart and Alain Prost have bowed out of the sport as reigning world champions and many feel that Schumacher is a character who would plan his exit while still on top.

Stewart won the championship in 1973 at Monza but then completed the year, although he failed to start his 100th and last Grand Prix when the Tyrrell team pulled out of the US Grand Prix as a mark of respect to team mate Francois Cevert who was killed in practice at Watkins Glen.

Schumacher, although happy in the immediate aftermath of the Belgian Grand Prix, was also deeply thoughtful, as if something was weighing on his mind.

"I would obviously rather have finished the championship with a victory," he admitted, "but today we simply weren't strong enough at the right moments and that's the way it is."

It would have been a bit more of a regret if, secretly, he knew that it had been his final race. And it might explain why, in the words of Ross Brawn, he "drove a very cautious race trying not to take any unnecessary risk". Alain Prost, last time up at Adelaide in 1993, said that he was more concerned with finishing his last race than with battling Ayrton Senna. In Michael's case, he could merely have been making sure of the championship, but could there have been more to it?

All speculation admittedly. The other way to look at it is that Monza is next, Ferrari's home territory, and of course Michael will host a press conference having just achieved a record-extending seventh world title. You would expect nothing less. But you can't help the nagging doubt. There would be a perfect symmetry about ending it all at Spa, where you came in...