In an interview in Tuesday's editions of French sports daily L'Equipe, Vinokourov said he has lived with a sense of "enormous injustice" since he was kicked out of the 2007 Tour de France after testing positive for a banned blood transfusion.

"With time, I understood that I would not live with that forever and I felt the need to ride again to show who I really am," Vinokourov was quoted as saying.

He added his return from retirement, announced last week, aims "to show that I am a clean rider."

After serving a one-year doping ban, the 35-year-old Vinokourov said he plans to ride competitively for two years.

He said he plans to join Team Astana, which is based in his native Kazakhstan. Seven-time Tour champion Lance Armstrong, who announced last month his return from retirement, is also expected to ride with Astana.

Vinokourov said he would have "no problem" riding alongside Armstrong - whose advocacy on behalf of cancer patients Vinokourov called "remarkable."

"My opinion of Armstrong has changed a lot since his retirement," the Kazakh cyclist was quoted as saying.

Still, Vinokourov said that unlike the 35-year-old Armstrong - who has said he aims to win an eighth title at the world's premier cycling event - he has not set the bar too high.

"I am not shouting from the rooftops that I am going to win the Tour de France," Vinokourov was quoted as saying. "At my age, that seems risky."