Contador, who won the Tour in 2007 and 2009, sits in third place overall 4:25 behind the British rider and 11 seconds adrift of Bauke Mollema of the Netherlands.
He lost a considerable amount of time in the two mountain-top finishes at Ax-3-Domaines and on Mont Ventoux, as well as in the first individual time trial as Froome showed he was unbeatable on a single climb.
The terrain is changing, however, as the race enters the Alps, with Thursday's 18th stage to l'Alpe d'Huez and Friday's 19th stage to Le Grand Bornand putting multiple ascents on the menu.
Froome was quickly isolated from his team-mates in the second Pyrenean stage after repeated attacks from rival teams, who failed to capitalise.
"My goal is to win but it is true that the leader is a level above and he cannot be beaten face to face but it will be a very demanding last week with more tactical options because there are back-to-back climbs and for me finishing second or 10th is not important," Contador said.
Contador, one of five men with titles in all three grands tours (France, Italy and Spain), has already set his sights on a particular stage.
"There is a stage where I want to see what can happen, where I could seize an opportunity," he said, without identifying the stage.
"The rest will depend on how the race pans out but if I see an opportunity I will go for it."
While he could make his move in the stage featuring two ascents of l'Alpe d'Huez, Contador is surely thinking about the 19th stage, which has two out-of-category climbs - Col du Glandon and Col de la Madeleine - in the first part and two first-category ascents - Col de l'Epine and Col de la Croix Fry - in the second part.
Tactics would consist of isolating Froome from his team mates on the first climbs and gaining some distance on him on the flat parts, as Contador's Saxo-Tinkoff showed they could do when they trapped the Briton behind with an acceleration away in last Friday's flat stage.
"They found Sky's weakness," Irishman Dan Martin, who won the second Pyrenean stage, told Reuters.
Martin said Sky's rivals had made an error that day in attacking Froome only on the climbs.
"That's a mistake they made the day I won: I was expecting a lot more attacks in the valley. They are not going to drop him in the climbs," he said.
Contador has already shown that he has the tactical nous to overthrow Froome, even if, with a four-minute deficit, the odds are stacked against him.
In last year's Vuelta, Joaquim Rodriguez had the race firmly in his hands when Contador launched a surprise long-range attack that gave him the overall lead after the 17th stage and eventually the title.
"There are two important differences. Firstly, the leader is further away and that makes everything more difficult. Secondly, he (Froome) has been stronger, while in the Vuelta we basically had the same level."
This is not enough to discourage Contador, who appears a much quieter person since he lost his 2010 Tour de France title following a doping test.
"It is true that year after year you evolve and perhaps I'm calmer than some years ago," he said. "I may be calmer in the important stages."
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