Milan - Belgian rider Tim Wellens has pulled out of the Giro d'Italia before Saturday's 14th stage to the summit of Monte Zoncolan because of a fever.
The 27-year-old Lotto-Soudal rider had won a sprint finish for the fourth stage between Catania and Caltagirone in Sicily.
But his team said he has been suffering from a sore throat and signs of bronchitis, and had a fever after Friday's stage.
"It's never fun to abandon a Grand Tour," said Wellens in a statement.
"Thanks to my stage win I can say my Giro has been a success, but I would have loved to aim for a second victory.
"The past days I had a go, but I could not take enough advantage.
"Already after the move from Israel to Sicily I felt as if I couldn't catch up on sleep and that didn't improve with the move to the mainland."
Briton Simon Yates of Mitchelton is wearing the leader's pink jersey going into Saturday's stage which could be key to overall victory.
The race starts in San Vito al Tagliamento and covers 186km with four climbs before the final 10.5km ascent to the summit of Monte Zoncolan in the Carnic Alps between Austria and northeastern Italy, reputedly one of the toughest in Europe.