LUZ ARDIDEN, France, July 14, 2011 (AFP) – Three-time champion Alberto Contador admitted to suffering from an existing knee injury as he lost more time to key yellow jersey rivals on Thursday’s 12th stage of the Tour de France.

On the first of three days in the Pyrenees Contador lost 13secs to Andy Schleck and Cadel Evans — who share the past four runner-up places on the race — and 33sec to Frank Schleck.

While trying to play down his loss on the first day in the high mountains, Saxo Bank’s leader admitted he was in pain.

“I had a really sore knee, it was bothering me so I’m happy with the result even if I did concede a few seconds. I couldn’t do any better,” said Contador.

The Spaniard is now seventh overall at four minutes behind French race leader Thomas Voeckler. Crucially, he is 2:11 behind Frank Schleck, 1:54 behind Evans and 1:43 behind Andy Schleck.

Having lost over a minute to his rivals because of a crash on the opening stage, Contador has since been involved in another three spills that have affected his form and technique.

However with plenty of mountain action on the horizon, he hopes to come fighting back.

“I’ve been feeling the effects of those crashes in the first week, my pedal stroke hasn’t been great. But I’m sure things are going to improve,” added Contador, who won the race in 2007, 2009 and 2010.

“The engine is taking some time to warm up but I think everyone is feeling tired and I hope that will play to my advantage.”

For the first time in the race Contador fell victim to tactics that the Schleck brothers had threatened to employ in a bid to outfox him.

Andy Schleck, who has finished runner-up the past two years to Contador, looked a happy man at the end of the stage.

“Obviously today wasn’t decisive but we showed our strengths. Contador isn’t unbeatable, he lost more time today.”

Contador added: “I’m convinced things are going to improve for me. With a bit of ice my knee should be in good condition Saturday.”

Friday’s 13th stage from Pau to Lourdes does not finish on a mountaintop.