- Defending champion Bradley Wiggins withdraws from the 2013 Tour de France
- The British cyclist has failed to recover from an ongoing knee injury
- Wiggins was forced to pull out of the Giro d'Italia with a chest infection
- Wiggins was set to support Chris Froome's bid for success at this year's race
Defending Tour de France champion Bradley Wiggins has been forced out of this year's race due to an ongoing knee condition, the Briton's Sky Pro Cycling team announced on Friday.
Wiggins, the first British rider to win cycling's most prestigious event, withdrew from the Giro d'Italia with a chest infection on May 18 and he was scheduled to rest and train as well as receive treatment on his knee.
But the seven-time Olympic medalist, who has also withdrawn from the Criterium du Dauphine and the Tour de Suisse, has now ran out of time to adequately prepare for the Tour de France, which begins on the island of Corsica on June 29.
"It's a huge disappointment not to make the Tour. I desperately wanted be there, for the team and for all the fans along the way -- but it's not going to happen," the 33-year-old told Sky Pro Cycling's official website.
"I can't train the way I need to train and I'm not going to be ready. Once you accept that, it's almost a relief not having to worry about the injury and the race against time.
"I've been through this before, when I broke my collarbone, so I know how it works. I'll get this sorted, set new goals for this season and focus on those."
Team principal Dave Brailsford expressed disappointment at the news, although it had already been confirmed Wiggins would play second fiddle to compatriot Chris Froome at this year's Tour.
"With illness, injury and treatment Brad has gone past the point where he can be ready for the Tour," said Brailsford, who is also performance director of British Cycling. "It's a big loss but, given these circumstances, we won't consider him for selection.
"He hasn't been able to train hard since the Giro and now he needs further rest. Whilst we all know these things happen in sport, it doesn't take away from the fact that this is a huge disappointment for everyone in the team -- and above all for Brad.
'"It's incredibly sad to have the reigning champion at Team Sky but not lining up at the Tour. But he's a champion, a formidable athlete and will come back winning as he has before."
Team doctor Richard Freeman said Wiggins had completely recovered from his chest infection, but his knee was worse than first thought.
""The chest infection that caused his withdrawal from the Giro has responded to treatment and rest. It has completely cleared up," explained Freeman.
"However, further medical investigations on the knee injury that we were managing at the Giro showed the condition was more significant than we thought.
"It has needed intensive treatment and, whilst it will be fully resolved, Bradley now needs to rest completely for five days before a gradual, return to full training over a period of two to three weeks."
Wiggins was set to play a supporting role to Sky's lead rider Froome at this year's Tour.
Kenyan-born Froome finished second in last year's race and is one of the favorites to take the yellow jersey in 2013.