The Spaniard was previously banned for two years and stripped of two grand tour titles for a positive test for Clenbuterol despite proclaiming his innocence.
The Saxo-Tinkoff rider told TV2 in France: "For cycling, it should be zero tolerance... it is clear that there is no place for cheaters."
He added that he considers it an injustice that he had his 2010 Tour de France and 2011 Giro d'Italia titles taken from him.
"I worked according to the regulations and they said that the victory is not mine - it's an injustice," he said.
Riders returning from doping bans will not contribute to their team's points tally for two years, which has left Saxo-Tinkoff's future as a WorldTour team in danger after many of Contador's points were nullified.
The Danish team is vying with Argos-Shimano for the final licence.
"I would love to do the Tour obviously," said Contador. "I missed it this year. But if I only find out two months before, then I won't [be there].
"I need enough time to prepare. Otherwise I won't be a part of it."