Matt Damon, once touted to play Lance Armstrong in a film based on It’s Not About The Bike back when that book was still thought of as a factual biography rather than a work of semi-fiction, is now being seen as frontrunner to play the disgraced cyclist in a movie giving a slightly different version of his career.

Damon, known for playing such uncompromising characters as amnesiac assassin Jason Bourne and the identity thief-cum-psychopath Tom Ripley, is widely tipped to play Armstrong in a film based on Tyler Hamilton and Daniel Coyle’s book, The Secret Race.

The book was published in early September days after the United States Anti Doping Agency announced that it had banned Armstrong for life and stripped him of results including his seven Tour de France titles.

It’s now being reported that Damon – at 42, some 11 months older than Armstrong is now, and a good deal older than the Texan was in his prime, but nothing the make-up department and a bit of good old Hollywood magic can't fix – is in line to take the lead role.

However, one industry insider quoted in The Sun said that the absence of a happy ending – for Armstrong, presumably – may prove problematic.

“Most sports films end in an inspirational victory,” said the unnamed source. “It’s hard to work out what the ending would be.

“Lance was a hero before this scandal. The current ending is too depressing. It would be a more appealing story with a more hopeful final act.”

There have of course been plenty of factually based movies that don’t necessarily end with everyone living happily ever after – The Titanic, for example, or to cite one from Armstrong’s home state Texas, The Alamo (although ultimately, the Mexicans did lose).

While it was Damon who was originally viewed as the prime candidate to take on the role of Armstrong had It’s Not About The Bike ever made it into production, it was another actor, Jake Gyllenhaal who later emerged as the favourite to portray him.

In 2006, the Donnie Darko and Brokeback Mountain star even rode alongside Armstrong in the Discovery Channel team car following Yaroslav Popovych in the individual time trial on the penultimate day’s time trial in the Tour de France.

The following day would see Armstrong's former US Postal team mate Floyd Landis seal his overall victory – later, he'd be stripped of that title and of course was one of USADA's prime witneses in its recent investigation.

Armstrong, together with his agent Bill Stapleton, was also reported to have met with Tour de France director Jean-Marie le Blanc and his successor Christian Prudhomme to talk about permission to feature the race in the film, which was being developed by Sony.

Gyllenhaal himself became a big convert to cycling when preparing for a role he would never play, and last year promised a journalist from Men’s Journal magazine a “really fucking hard climb” in an interview conducted on a bike ride around the Hollywood Hills, as you do when promoting your latest movie.

So, assuming the rumours are correct, has the casting director got it spot on in selecting Damon for the Armstrong role? And what about the supporting roles – Hamilton, Landis, Hein Verbruggen, Johan Bruyneel, Michele Ferrari and Motoman? Who should play them?

Let's hear your suggestions in the comments below…