By Alasdair Fotheringham
BUSSETO, Italy (Reuters) - This year's Giro d'Italia claimed two major victims when pre-race favorite Bradley Wiggins and defending champion Ryder Hesjedal withdrew prior to Friday's 13th stage, the pair citing illness as the reason for abandoning the tour.
Wiggins enjoyed a stellar 2012 when he became the first Briton to win the Tour de France and backed that up with a time trial gold medal at the London Olympics before turning his attention towards adding to those titles in Italy.
He looked strong early in the 21-stage race but gradually slipped out of contention, blaming his poor performance on a chest infection that eventually led to his withdrawal.
"Due to a worsening chest infection, the decision was taken for Wiggins not to start the race's 13th stage on Friday from Busseto to Cherasco," his Team Sky said in a statement, adding that Colombian Rigoberto Uran, third overall, was the new team leader.
"We monitored Bradley overnight and this morning we've withdrawn him from the Giro after consulting the team doctor," team principal Dave Brailsford added.
"His chest infection has been getting worse and our primary concern is always the health of our riders.
"Bradley will return to the UK today for treatment and to rest and we hope to have him back on the road as soon as possible. As a passionate racer he wanted to continue but he is simply unable to do so on medical grounds."
After losing more than three minutes on the main contenders on a wet 12th stage, Wiggins was lying 13th overall, 5:22 adrift of leader Vincenzo Nibali of Italy.
The Briton's withdrawal came shortly after defending champion Hesjedal also abandoned the race, with the Canadian's Garmin-Sharp team announcing the news earlier on Friday.
Hesjedal had slipped to 38th place, 32 minutes and 55 seconds down on Nibali after suffering badly in the first mountain stages of the race last weekend.
"It's heartbreaking," Hesjedal said in a news release.
"I want to be here for my team and for all the people who have supported me to get me here to this point.
"I built my entire season around the Giro and I came here feeling great, but I have been suffering since the (stage eight) TT (individual time trial).
"We're working on it but we're not sure what's wrong. There's a virus that's been going around, so it could be that, or severe allergies."
Hesjedal became his country's first Giro d'Italia winner when he edged out Spain's Joaquim Rodriguez by 16 seconds after a ferocious two-week duel through the mountains, with the Canadian gaining the upper hand on the final day's time trial in Milan.
Wiggins and Hesjedal's withdrawals follows that of France national champion Nacer Bouhanni, who announced on Thursday evening that he was quitting the race.
Friday's 254-km stage favors the sprinters and runs from Busseto to Cherasco with this year's race finishing in Brescia on May 26.
(Additional reporting by Julien Pretot; Editing by John O'Brien)