A career that seemed destined for greatness was stopped in its tracks the moment Fernando Alonso's solicitor walked out of the McLaren headquarters this morning with the divorce papers in his briefcase.

Luis Garcia Abad had spent two days negotiating with McLaren's lawyers in an effort to extricate his client from a marriage that simply didn't work with the least possible alimony to pay. If Alonso got away without having to write an enormous compensation cheque, then the damage inflicted on his career will be savage, for Alonso will have no chance of adding a third world title to his tally next season.

Ron Dennis, McLaren's team principal, was clearly desperate to draw a line in the sand after an unhappy year with a driver he clearly believed could have fulfilled his destiny at McLaren. But Dennis is still a fierce competitor and it is surely beyond the realms of possibility that there were not conditions attached to the deal to sever the Spaniard's contract a year early. That will probably mean ruling any teams likely to mount a world championship challenge off limits - and that would include Ferrari.

It seems more than likely Ferrari knew the plot when they renewed Felipa Massa's deal with the Scuderia and Jean Todt, Ferrari's wily team pricipal, has been around the block enough times with his old adversary to know that Dennis does not give away an easy advantage. So what will happen to Alonso now? Flavio Briatore, Renault's team principal, has been hanging on for the youngster he discovered and then steered to two world championships before deciding on his driver line-up for next year. But Dennis may still regard Renault, in spite of a lacklustre 2007, as a potential threat, which starts to reduce Alonso's choices considerably.

Red Bull has often been mentioned as an option; the are improving fast under the guidance of Adrian Newey, the chief designer who, coincidentally, was Dennis's right-hand man for almost a decade, and they would have the money to match the £13.5 million salary Alonso was getting at McLaren. Alonso's profile would be good for the multi-national drinks firm - but it is a stretch of the imagination to think that a Red Bull car will be at the top of the Formula One podium next season.

Whichever way it pans out, Alonso will be marking time, a penance for his part in a year of intrigue and unhappiness at a team he once dreamed of driving for.