International Cycling Union (UCI) president, Ireland's Pat McQuaid, said he would not be happy to see Michael Rasmussen win the Tour de France.
The Dane, who is the race's overall leader, has received two warnings from the UCI for failing to provide details of his whereabouts while training.
A rider has to give the sport's ruling body his personal schedule so that random dope tests can be conducted.
'From an image point of view, it would be better if it was not Rasmussen but one of the youngest riders winning the Tour,' McQuaid said.
'But he has not broken any rule so far since two no shows are not a doping offence.'
The Rabobank rider has been dropped from the Danish national team for the world championships and the Olympic Games in Beijing next year.
Rasmussen has refused to comment on doping matters since the story of his warnings broke last Thursday and has said he would answer questions only about the race.
However, he told reporters after today's stage: 'That's news to me. I have done everything to win this race. I have no intention of giving up now.'
McQuaid said last week a third no show by Rasmussen would be considered as a positive test and he would then face suspension for two years.
The Tour's image took a battering last year when winner Floyd Landis tested positive for excessive levels of the male sex hormone testosterone.
The American, who has protested his innocence, is still awaiting a ruling from a United States arbitration panel. If the decision goes against him, he could become the first Tour winner to be stripped of his title.
McQuaid added that the teams who had failed to sign a new version of the UCI anti-doping charter had another fortnight's grace.
'They have until 7 August to sign it. For those who will not do it, we will deal with them on a case-by-case basis,' he said.
All the riders on the Tour, which ends in Paris on Sunday, have signed the charter but by Monday staff from only two teams, AG2r and Credit Agricole, had returned the document to the UCI.