Tiago Machado's hopes of helping Radioshack teammate Lance Armstrong win an eighth Tour de France in July have been dashed by team manager Johan Bruyneel, who believes the prospect lacks experience.

Portugal's Machado, who joined the American outfit during the close season, has been in impressive form with a third place overall finish in the Tour of Algarve and second in Saturday's hilly opening stage of the Criterium International.

"I saw nice things from him last year, he has great qualities," Bruyneel told Reuters on Sunday.

"He is discovering what real professional cycling is about this season. He can be impressive but he still has a lot to learn."

The 24-year-old Machado also showed his class in the 2010 Paris-Nice stage race earlier this month, often attacking in the climbs.

Those performances would naturally put him on a team shortlist of riders earmarked to help Armstrong in the mountains for the July 3-25 2010 Tour de France but Bruyneel insists the race has come too soon.

"No, it's impossible (that he rides the Tour)," the Belgian commented. Bruyneel added "He still has too much to learn. He still does not really know how to place himself in the bunch, he takes too much wind."