Landis, whose victory was put in doubt after his team said he tested positive for high testosterone levels, won't appear on the NBC talk show Friday as planned, a network spokeswoman said Thursday.
The show was informed by a representative for Landis that he was still in Europe and unavailable, the spokeswoman said. The "Tonight Show" remains interested in having him on, she added.
NBC announced Wednesday that Landis' first talk-show appearance since winning the race Sunday would be with Leno on "Tonight" — then came the announcement Thursday from his Phonak team that he had been suspended pending results of a backup sample of his drug test.
If Landis, of Murietta, is found guilty of doping he could be stripped of the Tour title and fired from the team.
In a late Thursday news conference conducted by telephone from somewhere in Europe, Landis said he was innocent of doping and he hoped to get a chance to prove he didn't cheat to win the race.