The three-time Tour de France winner Alberto Contador, the greatest stage racer of his generation, is aiming for a fourth victory in 2011.
Now riding for Team Saxo Bank-SunGard under the stewardship of Bjarne Riis, Contador won this year's Giro d'Italia, proving he has the form to go with his status as Tour de France favourite for 2011.
But there is a shadow looming over Contador. During last year's Tour de France the Spaniard, then riding for Kazakhstan-backed Team Astana, he tested positive for the banned substance clenbuterol.
Contador protested his innocence, insisting the substance came from contaminated meat. The Spanish Cycling Federation accepted this explanation and cleared him to continue racing, a decision challenged by the UCI (International Cycling Union).
So Contador will race this summer, before facing the challenge of the UCI at the Court of Arbitration for Sport (CAS) between August 1-3. Should he lose the case, he will be stripped of his 2010 Tour title and also of whatever result he achieves this year.
The failed clenbuterol test is not the first time Contador has been associated with suspicions of doping, after he name was linked to Spain's "Operacion Puerto" in 2006. but regardless of the current focus on that case, his achievements in the saddle place him alongside some of the greatest riders of all time.
The 28-year-old, nicknamed "El Pistolero" (The Gunman), is one of only five riders to win the "Triple Crown": the Tour, the Giro d'Italia and the Vuelta a Espana.
Contador's first speciality was climbing, but his improved time-trialling and all-round ability have seen him become one of the most feared cyclists in the world.
Born and raised in Madrid, the precociously talented Contador was first nicknamed "Pantani" as a teenager owing to his prowess in the mountains, after the late Italian legend Marco Pantani.
Contador won his first Tour de France in 2007 riding for the Discovery Channel team, following Michael Rasmussen's expulsion amid accusations of doping.
The following year he won the 2008 Giro d'Italia, completing the hat-trick of cycling's Grand Tours.
In 2009 he found himself riding in the same power-packed Astana team as seven-time Tour winner Lance Armstrong.
The Texan had vowed to ride in support of Contador before the race, but his position changed after he grabbed a narrow advantage over his younger rival.
"We've got it going with two leaders," Armstrong insisted, setting up one of the great stories of cycling. But Contador dominated Armstrong in the mountains and comfortably beat Armstrong into third place with Andy Schleck second.
The current controversy threatens a burgeoning rivalry with Schleck. "Chaingate" was undoubtedly the most dramatic moment of the 2010 Tour de France.
In trying to turn up the heat on Contador, the Luxemburger Schleck lost his chain on Stage 15. Contrary to some riders' unwritten ethical code, Contador pulled away - eventually winning the Tour by the 39 seconds - precisely the amount of time he gained while Schleck struggled to get his chain back on the ring.
Schleck left Saxo-Bank last year to join the newly formed Team Leopard-Trek. Schleck and Contador are the favourites for overall victory this year, and the Leopard-Trek team will be Saxo-Bank's main threat.
The last word on Contador's tour performance may not be spoken on the Champs Elysées on 24 July, but in Lausanne at the Court of Arbitration for Sport a month later.