Alberto Contador says it will be "ridiculous" if he is stripped of the Tour de France title should he again win the event which starts on Saturday.
The Spaniard tested positive during his victory last year and though cleared he is awaiting results of an appeal.
"From the beginning of the season I've been the rider who's had the most doping tests, and I've been tested in all the races I've been in," he said.
"The idea victory could be taken away if I win, I just find ridiculous."
Contador is seeking to become the first man for 13 years to complete the Giro d'Italia and Tour de France double as he defends his title, starting in Passage du Gois in the Vendee region of western France.
The late Marco Pantani was the last rider to achieve the feat.
Contador tested positive for banned substance clenbuterol on the second rest day of last year's Tour.
He was cleared of wrongdoing by the Spanish federation but the International Cycling Union and the World Anti-Doping Agency appealed against the verdict.
The Court of Arbitration for Sport will not hear the appeal until August, meaning that Contador - the overwhelming favourite - could be stripped of all his victories since and including last year's yellow jersey triumph at Le Tour.
The Spaniard has had a winning habit this season, snatching nine victories and using his outstanding climbing abilities to dominate the field in the Giro.
However, the 28-year-old admits his current form is something of an unknown quantity after his exertions in Italy.
Contador said: "As time goes by, I feel more and more rested [after the Giro] but I'm still a bit in the dark because all I did was rest.
"I don't know how I will respond. Undoubtedly, [compared to those who did not ride the Giro], I lack physical but also mental freshness.
"I'm very conscious of the fact there has been more pressure on me off the bike, but all I can try and do is fully concentrate on the race.
"I have to try not to lose focus and get on with what needs to be done to win."
Andy Schleck, who has finished runner-up to Contador in the last two years, will once again be the defending champion's top challenger.
Schleck left Saxo Bank to launch his own outfit, Leopard Trek, with several others. They include his brother Frank and the Olympic and world time trial world champion Fabian Cancellara.
This year's route will favour climbers and the race is likely to be decided during a tough third week in the Alps.