Wiggins, 29, is a three-time Olympic gold medallist on the track
Alberto Contador believes Bradley Wiggins poses the biggest threat to his hopes of winning the Tour de France.
The British rider is third, one minute 46 seconds behind the Spaniard, as the Tour enters its third and final week.
Contador captured the yellow jersey on Sunday with an attack up Verbier that helped him win the 15th stage.
But he said: "I have to put as much distance as possible between us in the mountain stages because he (Wiggins) is a strong contender in the time-trials."
The race spends two more days in the Alps before Thursday's individual time trial in Annecy.
Contador finished 66 seconds ahead of Wiggins on the climb to Verbier but the British rider's efforts did not go unnoticed.
"Bradley did sensationally in the climb up to Verbier and he is going to have to be taken into consideration," Contador added in French paper L'Equipe.
I'm not stupid enough to think I can beat Contador... he's proved by far he's the best rider in this race
"He is a surprise. He was already in incredible shape, but now he has proved to be a real stage race rider. He is one of my biggest contenders and I am sure he will be dangerous in Annecy in the time trial."
However, Wiggins has moved to dampen expectations after two-time runner-up Cadel Evans also said the Briton was capable of winning this year's Tour de France.
"I'm not stupid enough to think I can beat Contador," said Wiggins, who rides for the Garmin-Slipstream team. "He's proved by far he's the best rider in this race.
"I knew I was physically capable of a top 15 or 20 finish but right now I'm not looking too far ahead.
"Anything can happen from one day to the next. I could have lost four minutes in the first week because of splits and crashes. We're just looking at one day at a time. Tuesday's another tough stage.
"I'll get through that first, then the next day, then the time trial and then get through Mont Ventoux. Paris is a long way off yet. The race is by no means done yet."
Wiggins, a three-time Olympic gold medallist on the track, has been one of the success stories of this year's Tour, staying in the top 10 from the very start and more than holding his own on the punishing mountain stages.
"He's climbing really well and knows how to ride on the flat," said Evans. "As an athlete he's shown he's very talented.
"It will be interested to see how Wiggins does in the time trial. The third week will be the toughest test for him."
Wiggins is not the only rider still in contention and Contador knows he faces competition from those in the current top five, particularly former Giro d'Italia runner-up Andy Schleck.
"I think Andy Schleck will be the most dangerous in the coming week and I think our biggest danger is if all the contenders work against us," said the Spaniard.
"I still miss something. It is not done yet. We have a very hard week to go. All the stages are difficult, but I think things will be decided on Le Grand Bornand (Wednesday) and on Mont Ventoux (Saturday)."
Alberto Contador can look strong and suddenly have a bad day, like in Paris-Nice this year
Schleck believes Contador is fallible and can be caught.
"We will continue to attack, even if we die in the process," he said.
"We have seen before that Contador can look strong and suddenly have a bad day, like in Paris-Nice this year. Back then he lost everything and went down. It may happen here as well."
Luxemburger Schleck is fifth, 2:26 behind Contador who leads seven-times Tour winner and Astana team-mate Lance Armstrong by 1:37 in the overall standings.
German Andreas Kloden, also of Astana, is fourth, 2:17 behind.