Utrecht - A doping-related scandal involving the tainted Astana team of Tour de France champion Vincenzo Nibali marred the start of the Grand Boucle in Utrecht on Saturday.
Late on Friday night, news emerged that Astana's Dutch rider Lars Boom had returned a low level of cortisol in an unofficial test conducted by the Movement for Credible Cycling (MPCC) earlier this week.
Under MPCC rules, which are not binding, Astana are obliged to stand down Boom for a period of eight days.
Boom's reading is not a doping violation - a high level of cortisol would be - but the MPCC rules state that the rider must be rested for his own health.
Astana, like another 12 teams competing at the Tour, are voluntary members of the MPCC and initially indicated their desire to respect the regulations.
However, their request to the International Cycling Union (UCI) to replace Boom with their reserve rider Alessandro Vanotti was refused as it came too late.
It left Astana, who are under increased scrutiny this year as a condition for having their licence renewed due to a string of doping scandals in 2014 - Kazakh brothers Maxim and Valentin Iglinsky both tested positive for the banned blood booster EPO while three riders on the secondary Continental Tour team failed tests for steroids - in a difficult position.
If they are to respect the MPCC rules, they would have to start the race with just eight riders, perhaps damaging Nibali's chances of retaining his crown.
Boom, 29, was expected to play an important role for Nibali during the first nine days. He won the cobbled fifth stage on last year's Tour and was expected to be Nibali's chief lieutenant during this year's similar fourth stage.
He's also a powerful 'rouleur' whose job it would have been to protect Nibali on fast flat stages like Sunday's second one from Utrecht to Zeeland where there is a risk of strong cross winds, while he is also a key element for the stage nine team timetrial.
However, if he lines up for Saturday's 13.8km individual timetrial around Utrecht at 16.55 local time (1455 GMT), Astana would be breaking MPCC rules and perhaps be forced to leave the movement.
Two other teams did in fact leave the MPCC earlier in the year over similar incidents.
While a low cortisol level is not necessarily a sign of doping, it can be produced by the use of glucocorticosteroids, an anti-inflammatory drug that can allow riders to break through the pain barrier.
However, it can also be caused by fatigue, while the use of glucocorticosteroids can produce fatigue and increase the risk of injury.
Astana indicated their intention to take Boom to the start, while UCI president Brian Cookson said that by doing so they would not be breaking anti-doping rules.
"Lars Boom has not broken any UCI or Wada rules, the issue of cortisol and cortisone has been referred to Wada's scientific experts and at the present moment they have not recommended we or anyone else take action to include that within our rules," Cookson told AFP.
"It's not included in the Wada rules so I can say Lars Boom is free to start the Tour de France under UCI rules, he hasn't broken any rules."
As for Saturday's opening stage, three-time world timetrial champion Tony Martin from Germany is expected to battle home hope Tom Dumoulin for the stage victory to become the first yellow jersey wearer of the 2015 Tour.
"Everybody's speaking about me and Tom but I already said a few times there are a lot more riders to look at," said Martin, who rides for the Etixx-Quick Step team.
"I wouldn't forget (Fabian) Cancellara, (Matthias) Brandle, Rohan Dennis; it's not just about Tom.
"For sure in the past he was the closest (to Martin). It will be a nice fight and I'm confident I can beat him again."
As for the 'fantastic four' overall contenders, 2013 champion Chris Froome believes he can put time into his rivals, Nibali, Giro d'Italia winner Alberto Contador and Colombian Nairo Quintana.
"It's definitely the start of the GC (general classification) race, even though it's such a short distance at just under 14km," said the 30-year-old Kenyan-born British Team Sky leader.
"There can be time gaps; I'd expect time gaps of at least up to 20 seconds between the GC contenders, so the race does start (Saturday) in that regard."
The timetrial was due to begin at 14:00 SA time with debutant Daniel Teklehaimanot - one of two Eritreans alongside Merhawi Kudus making history by becoming the first black Africans to race the Tour - first up.