(CNN) -- For Briton Bradley Wiggins 2013 is fast becoming a year to forget.
If 2012 was his annus mirabilis -- he became his country's first Tour de France winner before going on to clinch gold at the London 2012 Olympic Games -- then this year is in danger of turning into Wiggins' annus horribilis.
Earlier this month Wiggins discovered his teammate Chris Froome would be Team Sky's lead rider at next month's Tour de France, a decision that virtually deprives last year's winner of a realistic chance of defending the yellow jersey given a team's resources are harnessed to support their designated leader..
And now the seven-time Olympic medalist has been forced to withdraw from the Giro d'Italia -- a race which had become Wiggins' priority this season -- with a chest infection.
"We monitored Bradley overnight and this morning we've withdrawn him from the Giro after consulting the team doctor," said Team Sky team principal Dave Brailsford.
"His chest infection has been getting worse and our primary concern is always the health of our riders."
Wiggins was bidding to become the first British winner of the Giro, but he was laboring in 13th place overall -- five minutes and 22 seconds behind leader Vincenzo Nibali -- when he withdrew before the start of Friday's 13th stage.
Along with the Tour de France and the Tour of Spain, the Giro is one of Europe's three major professional cycling stage races
The 33-year-old Wiggins wasn't the only high-profile rider to withdraw, with team Garmin-Sharp's Ryder Hesjedal out of the race after succumbing to illness.
Like Wiggins, having also shaped his season around the Giro, Hesjedal said he was "heartbroken" at having to pull out of the race he won in 2012.
Brailsford hopes to have the London-born Wiggins back on his bike as soon as possible
"Bradley will return to the United Kingdom for treatment and to rest and we hope to have him back on the road as soon as possible," continued Brailsford, who is also team principal of British Cycling.
"As a passionate racer he wanted to continue but he is simply unable to do so on medical grounds."
Once Wiggins is back in the saddle, attention will focus on his rivalry with Froome, who finished second at last year's Tour de France.
Their rivalry is not only being played out on the road but also on Twitter.
"Chris & Brad on the same start line, in the same kit? Mmmmmm... doubt it!" tweeted Froome's partner Michelle Cound, following it up with "To those claiming that this Wiggins/Froome thing is some sort of publicity stunt, you are wrong."
"I look forward to@TeamSky clearing up this mess (ASAP) #fedup ."
Cound and Wiggins' wife Catherine were embroiled in a spat during last year's Tour de France, when Cound was irked by her Kenyan-born partner playing a support role to Wiggins.
The 2013 Tour de France begins on the island of Corsica on June 29.
Meanwhile, Britain's other great cycling star, Mark Cavendish, claimed his fourth win of this year's Giro after Friday's 254km leg from Busseto to Cherasco.
The sprint specialist held off home rider Giacomo Nizzolo to strengthen his lead in the battle for the red points jersey.
Nibali and the other major contenders for overall honors finished safely in the main bunch.