The 19-kilometre opening individual time-trial, held on a lonely causeway flanked by oyster beds and barnacles on France's west coast, will be long enough to ensure that important margins open up on the overall classification.
Would Armstrong, it was asked, be able to resist such an opportunity to strike a powerful early blow? His track record in Tour time-trials of this kind of distance or greater is more than solid - he has won eight out of a possible 12 since his run of six consecutive overall wins began in 1999.
Traditionally, the Texan has always used the Tour's usual prologue event - substituted this year by this much longer time-trial - as a first opportunity to demonstrate his strength, albeit over a much more symbolic, shorter, distance.
Then three days later, in the 60km team time-trial event, Armstrong's Discovery Channel squad are again the favourites, having won the equivalent stage for the last two years running - another opportunity for their 33-year-old leader to gain a more solid hold on the lead.
Twelve months ago, Armstrong moved into the yellow jersey as a result of his team's triumph, and then almost instantly ceded it to a rider who would not threaten his dominance long-term.
But given that this is Armstrong's final Tour de France - and with his place in sporting history already more than secure - he could well be toying with the idea of becoming the first rider since Romans Maes in 1935 to spend the entire race in the lead.
Significantly, he did not automatically discard such a possibility in his final pre-race press conference when asked if that was his objective, and replied instead that "this will be a highly significant opening time-trial".
"If there's a headwind, which is likely, then it's so flat and exposed it will feel more like a 30-kilometre event than one just 20 kilometres in distance," Armstrong said. "And the time differences will matter more."
Following the team time- trial there will follow a week of relative truce as the race cuts an eastward swathe through the plains of northern France before making a brief incursion into Germany. The route then includes a brief test of the riders' climbing form when it crosses the Vosges mountains near Strasbourg on the ninth stage.
But as France's leading cyclist of recent years, Laurent Jalabert, pointed out, "the really critical stages are the ones finishing on Courchevel in the Alps, the assault of the Galibier [the Tour's highest climb of the race this year] 24 hours later, and the final mountaintop finish on Pla d'Adet in the Pyrenees five days later."
For the past six years, Armstrong has always adopted the same tactic of crushing the opposition at the first opportunity in the mountains, and at Courchevel, where he suffered a rare defeat on the climbs in 2000, inflicted by the late Marco Pantani, his motivation to deliver a knockout blow is likely to be even higher than usual.
Given the solid form shown so far this year, there is little reason to doubt the Texan's ability to do so, for all that he recently sought to play down the pressure by arguing that "the older you get, the riskier and harder [winning] gets". But any signs that time is taking its toll will be ruthlessly exploited by his rivals - well aware that beating the American in his final race would grant them a considerable portion of reflected glory from the Armstrong myth.
Leading the opposition is the 1997 Tour winner, Jan Ullrich, whose close encounter with a rear windscreen on Friday - the glass shards came within millimetres of cutting major blood vessels in his neck - does not appear to have had any effects on his morale.
Others keen to topple the Texan include Ullrich's team-mate Alexandre Vinokourov, so admired by Armstrong that his team have already made the Kazakh an offer to ride for them next season.
There is not just the rising confidence of the challengers to give Armstrong the odd headache or two, either. On Friday evening his hotel was visited by medical inspectors carrying out a random doping check on the Texan.
It was Armstrong's sixth random control this season and the umpteenth reminder that from here until Paris, he will never be out of the spotlight. And it would be a typically Armstrong response to face such attention, unwelcome or otherwise, head-on - by winning the Tour from the gun.
Heirs apparent: Four to challenge Armstrong
The bridesmaid and not the bride ever since the Lance Armstrong era began in 1999, with a string of second places. He is determined to get his (sporting) revenge this year on the Texan before he quits. Should Ullrich win, he is strongly rumoured to be "doing a Lance" and retiring himself. But that requires toppling the Texan, and so far the German, who has always said Armstrong is beatable, has yet to walk the walk.
Third in 2004, the Italian was the only rider able to stick with Armstrong in the Pyrenees, although he was much weaker in the time trials. One year on, Basso's time trialling has improved, but he had a rocky ride in the recent Tour of Italy, winning stages galore but losing because of a stomach bug. Armstrong believes the combination of that disappointment plus better performances against the clock "make Ivan one of my most dangerous rivals".
Ullrich's T-Mobile lieutenant would be leader in any other team - and the 31-year-old Kazakh knows it only too well. Third in the 2003 Tour, Vinokourov is one of the most aggressive riders, but his attacking style will be curbed by Ullrich's more conservative approach. Already talking of moving on in 2006, Vinokourov has promised to work for Ullrich if the German is in yellow. But the Kazakh could well have his own plans should Ullrich come to grief.
Born into a wealthy family from Medellin, with a degree in economics and a natural gift for time trialling, Botero is anything but the archetypal Colombian cyclist. His wildly erratic career has World Championships and Tour mountain and time-trial stage wins as highlights. Following two disastrous years at T-Mobile, at 32 Botero has found his feet once again in the Swiss team Phonak - and could prove tough for Armstrong to shake off.Reuse content