Lance Armstrong has offered to teach Alberto Contador how to relax, saying the Spanish rider is too nervous.

"It is obvious he still has a lot to learn," seven-times Tour de France winner Armstrong said in an interview with French sports daily L'Equipe. "He is the best rider in the world but the only negative point, and I respectfully say that, is that he is too nervous... he is too good to be so nervous."

Last week, Armstrong said his Astana team-mate had much to learn after watching him collapse in the penultimate stage of the Paris-Nice race while wearing the overall leader's yellow jersey.

Armstrong came out of a 3-1/2-year retirement this season and will partner the 26-year-old Contador in the Tour in July.

Contador, who won the Tour in 2007 and both the Giro and the Tour of Spain last year, and Armstrong will race together for the first time in next week's Tour of Castilla.

"Contador can learn from me and from (Astana manager) Johan (Bruyneel)," the 37-year-old American told L'Equipe.

"I know a lot of things about cycling and the best thing to learn is how to relax. That is why we have decided to race together in the Tour of Castilla."