David Coulthard

It would have been inconceivable at the start of the season to believe that Coulthard, the second most successful driver on the F1 grid in terms of wins, would have to face up to the fact that this may be his last in grand prix racing.

The early season form of McLaren may have been disastrous for anyone looking for a drive elsewhere, but Coulthard's determined effort on the track and mature approach off it proved that he was more than worthy of consideration elsewhere. With his single-lap qualifying wobbles now a thing of the past, Coulthard looked like a man ready to prove a point if given the opportunity.

The man himself clearly feels that he still has plenty to offer in F1, but for teams there are the obvious reservations about his ultimate potential. At 33, it is clear that Coulthard is nearer the end of his career than the beginning and, alongside Mika Hakkinen and Kimi Raikkonen, he left the impression of being a more than competent number two rather than an out-and-out top rank number one - even if results on the track have not always justified such a feeling.

Coulthard remains realistic about the situation. Speaking about whether his recent strong performance in Japan has made him more confident about staying in F1 next year, he shrugs his shoulders and concedes that there can be no guarantees in the sport unless signatures are on bits of paper.

"Well, until you actually sign a contract you can't actually say it," he said. "I hope Brazil won't be my last Grand Prix, but the fact is that I don't have a contract for next year. But I'm not ready to stop racing so I'll keep chasing a seat for next year. And I'm not ready to go and race something else.

"So I'll do whatever I can to make sure I'm on the grid next season and if I'm not then I'll do whatever I can to make sure I'll be in a position to race somewhere else."

Earlier in the season there was talk of interest from Williams to team him up with Mark Webber for an ultra-strong partnership twinning experience with youth, but those plans fell through when the team found out that Mika Hakkinen was sniffing around for an F1 comeback and then that Jenson Button was available.

With that avenue apparently shut off in the initial days after 'Button-gate', Coulthard's name was linked as a possible shoe-in at BAR. His supporters claimed his experience, speed and captivating character would have been ideal for the team, while the doubters claimed he just did not have the title winning ability or youthful image that team owner British American Tobacco needed. As Anthony Davidson continued to shine on Fridays too, so Coulthard's chances diminished if Button did not stay.

Then, of course, there was Jaguar Racing. The team was after a number one driver to replace Williams-bound Mark Webber and in Coulthard it would have the kind of experience, personality and star it needed. Above all else he was every match for Webber in the all-important motivating stakes. It is understood a provisional deal was agreed between team and driver, but then it all fell apart when Ford pulled the plug on the outfit.

The closing off of these opportunities has left Coulthard without anything with just one race of the campaign remaining. His only realistic hope now is that this Saturday's ruling of the Contracts Recognition Board gives a final conclusion to the Button affair - and then he can put all his efforts into grabbing the seat that Button does not get.

To endorse his credentials, Coulthard will then need to put in a blistering performance in the Brazilian Grand Prix to help remind the sport about just what he can do. The next two weeks are therefore absolutely crucial for Coulthard.

The difficult thing for Coulthard now is putting in the kind of performance that will give teams the evidence they need to quell any doubts they have about him. Suzuka appeared to be giving him such an opportunity, as he pushed hard for a podium finish, and it must have been galling to see his chance blown away thanks to some over exuberance from Rubens Barrichello.

But rather than curse his misfortune at what happened, Coulthard stayed dignified about such bad luck coming at exactly the wrong time - claiming that the Barrichello incident was perhaps payback for him shunting Ralf Schumacher out of the race in Shanghai.

"If I had not run into Ralf in China I probably would be a bit more aggrieved with him now, but that's pretty much what I did in China. I took a gamble and it didn't work. So if you're going to give that out, you have to be ready to take it sometimes too.

"It's a pity because it was a very strong race for me all the way through. We had Sato covered, so that was fourth place guaranteed, which would be one of our better results this year. So, it is disappointing, but that's racing."

Coulthard feels, however, that despite his poor luck that Japan was some vindication for the job he can do when needed to.

"Well, I was the quickest McLaren on the track the whole weekend, from free practice to qualifying to the race, either in the wet or in the dry. Okay, this is just one race of the season but it goes to show that I've still got the pace and the commitment, plus the overtaking ability, but with a slight bigger element of caution than I had in China."

Brazil may only be one race too. But it looks set to be the most important one of David Coulthard's career.