Tour de France 2010
Start: 3 July, Rotterdam Finish: 25 July, Paris
Coverage: Listen to the final hour of every stage on the BBC Sport website (UK only), with selected stages on BBC 5 live sports extra; Watch live on Eurosport and ITV4; Live text commentary each day on BBC Sport website
Contador (right) and Armstrong endured a testing rivalry last year
Tour de France favourite Alberto Contador believes seven-time champion Lance Armstrong could derail his bid for a third title in four years.
The Spaniard endured a fractious relationship with the American as Astana team-mates in last year's Tour.
But asked if Armstrong could mark his final Tour with an eighth win, Contador said: "Absolutely and on his own merit.
"Last year he got third place and this year he is riding at a very good level. He will be fighting for victory."
Armstrong, who will be 39 in September, announced earlier this week that the 97th Tour de France will be his last.
The Texan criticised Contador for not following the Astana team's game-plan when the pair both had designs on overall victory during the 2009 Tour, with the Spaniard responding that there had been "a tendency to prioritise other people's interests", even though he proved himself the strongest rider.
Everyone appoints you as the clear favourite and this is a handicap
Armstrong took the majority of his Astana colleagues with him when he established Team RadioShack, who, like BMC Racing and British squad Team Sky, will be making their Tour debut.
Asked the extent of his relationship with Armstrong now, Contador says: "The truth is that we have no relationship at all, but I respect him as a great rider and champion."
The 27-year-old, who has four fellow Spaniards, an Italian, one Ukrainian and two Kazakhstanis - including Alexandre Vinokourov - as Astana team-mates this year, could join an elite group of riders if he triumphs again this year after his victories in 2007 and 2009.
Only eight men - Armstrong (seven victories), Jacques Anquetil, Eddy Merckx, Bernard Hinault, Miguel Indurain (all five), Philippe Thys, Louison Bobet, Greg Lemond (all three) - have won the Tour three times or more.
Contador, one of 12 cyclists to have won it twice, insists he "does not think in figures" and has no particular target of victories in mind. He is also uncomfortable with the favourites' tag.
"Victory is the aim for which I'm training," he added. "I know that is very difficult, because everyone is waiting to see if you fail and they will look to exploit any sign of weakness, but to me victory is a great goal and a challenge.
"It is a year in which everyone appoints you as the clear favourite and this is a handicap.
"The surprise factor is minimal and any time you fail, people will be there to exploit it."
With the performance he had last year I think [Wiggins] is a contender for victory
Contador, who is confident of his fitness and form despite withdrawing from the defence of his Spanish time-trial title last week with flu, is expected to perform well in Saturday's opening 8.9km prologue in Rotterdam.
He anticipates a "tough" first week, where cross winds and cobbled sections could have a significant impact and "the differences may be greater than in the mountains."
But he has no doubt which stages will decide the overall winner.
"It will be all of the Pyrenees [in the final week], because they are four very demanding days," he added.
"The [Col du] Tourmalet is the last chance, the last opportunity for the climbers to attempt to create or cut differences."
Contador admits 2009 runner-up Andy Schleck was the rider "who put me most in trouble" en route to victory, while he also believes Britain's Bradley Wiggins is capable of reaching the podium, or better.
"He focuses the whole year thinking about the Tour," he noted. "With the performance he had last year I think he is a contender for victory."