Lance Armstrong confirmed his return to top-level cycling on Wednesday - but admitted his doubts as to whether he can still compete for honours.
Armstrong announced he would be seeking an entry into the 2009 Tour De France as a member of the Astana team at a press conference in New York.
Armstrong retired in 2005 following his seventh consecutive victory in Le Tour but will resume his road racing career in a bid to raise awareness of cancer issues through his 'Livestrong' programme and the Lance Armstrong Foundation.
He will be reunited with Johan Bruyneel, his former sporting director at US Postal and Discovery, with whom the Texan won all seven of his Tour de France crowns, and will make his Astana debut in the Tour Down Under in Australia in January.
Asked if he could win the Tour de France for an eighth time, Armstrong was unsure.
"I honestly don't know," he said.
"I've been off the bike for three years and next summer it will be almost four years. With that is also the fact that I'll be almost 38 years old at the start of the 2009 Tour, so I don't know.
"I will try and be as prepared as possible. I don't know if that equals victory."
Armstrong's number one priority, he said, was the fight against cancer. The American contracted testicular cancer in 1996, which spread to his brain and lungs, but came through rigorous treatments and chemotherapy to return to cycling three years later and begin his domination of the Tour de France.
"Carrying the Livestrong message around the world, whether it be on a bicycle or through the media is the number one goal," he added.
Armstrong admitted a reunion with Bruyneel was realistically his only option when deciding which team to return with.
"While we looked at other teams and we talked with other teams, I can really trust Johan on every little decision. I could not imagine racing against him or without him," he said.
"So Johan and I will be together in 2009 and my first race will be in Australia, the Tour Down Under.
"The only other races I can say I'm doing for sure are the Tour de France and the Leadville 100."
The latter of those is a mountain bike race Armstrong competed in this summer in Colorado. He came second and later revealed the race had helped him realise that "I truly love to ride bikes for long hours every day".
Brunyeel is presently directeur sportif at Astana, which has suffered from two doping scandals to high-profile team members Andrei Kashkin and Alexander Vinokourov, both of whom were barred from the 2008 Tour de France and are currently serving bans from the sport.
Astana has also seen success, however, with team leader Alberto Contador winning the Giro D'Italia and Vuelta a Espana this year. Yet Contador on Tuesday expressed concerns that his status within the team would be compromised by the arrival of Armstrong.
In response, Armstrong was adamant he was not a threat to the Spaniard.