Britain's Bradley Wiggins, the winner of last year's Tour de France, has pulled out of the Giro d'Italia cycling race due to illness, his team announced on Friday.
"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," Team Sky said in a statement.
He had struggled in the race after a head cold turned into a chest infection.
He dropped more than three minutes off the pace during Thursday's 12th stage, struggling on a slippery descent to finish in 13th place overall, 5:22 minutes behind the current leader, Italy's Vincenzo Nibali, of Astana.
"We monitored Bradley overnight and this morning we've withdrawn him from the Giro after consulting the team doctor," team principal Dave Brailsford was quoted as saying on teamsky.com.
"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," he said.
At 254 kilometres (158 miles), Friday's 13th stage is the longest of the race, from Busseto, the birthplace of composer Giuseppe Verdi, to Cherasco.
Giro d'Italia is one of cycling's most prestigious races and Wiggins had made the Giro's 'maglia rosa' his primary objective before the sport's biggest showpiece, the Tour de France in July.