Former Giro d'Italia winner Ivan Basso withdrew from the Tour de France on Monday after revealing he has testicular cancer.
Jan Ullrich, Ivan Basso and Francisco Mancebo were named in a doping investigation in Spain
The American may let others battle it out for a podium place or a secondary classification in the 17th stage of Tour de France.
The American's pursuit of a record sixth Tour de France victory gained momentum on when he won the first Alpine stage to reclaim the yellow jersey from Thomas Voeckler.
The American won the 13th stage of the Tour de France and now trails Frenchman Thomas Voeckler by just 22 seconds.
Chris Froome and Alberto Contador were back in control of the Tour de France, hurting their main rivals in a hectic second stage won by German Andre Greipel on Sunday.