Juan Ayuso will not take the start of Friday's sixth stage of the Critérium du Dauphiné after suffering a fever and stomach problems.
The talented young Spaniard was lying in eighth place overall following a strong result in the mid-race time trial and lay 1:58 down on race leader Wout van Aert (Jumbo-Visma).
However, his UAE Team Emirates team announced on Thursday morning that Ayuso would be forced to leave the race due to his illness.
"Sadly, Juan Ayuso fell ill yesterday with fever and will not start today's stage of the Dauphiné," the team announced.
"Juan complained of a stomach discomfort and diarrhoea prior to yesterday's stage," said team doctor David De Klerk. "He was treated appropriately, but later developed a fever and mild dehydration.
"We performed a Covid test which returned negative but upon review this morning, his fever had not abated, and his condition had not improved overnight. He was therefore withdrawn from further participation in the event."
The news represents a major blow for UAE Team Emirates, with the 19-year-old representing the team's best chance at a podium finish ahead of the closing pair of mountain stages at the weekend.
Ayuso turned pro with the team in the middle of last season following his dominant victory at the U23 Giro d'Italia and has impressed in 2022. So far, he has finished second at the Trofeo Laigueglia, fifth at the Volta a Catalunya, and fourth at the Tour de Romandie.
The closing stages of the Dauphiné would have seen him do battle with the likes of Jumbo-Visma trio Van Aert, Primož Roglič, and Jonas Vingegaard, as well as Damiano Caruso (Bahrain Victorious), Tao Geoghegan Hart (Ineos Grenadiers), all of whom lay ahead of him on GC.
UAE Team Emirates will now turn to Brandon McNulty, who lies in 18th place at 2:45 off the race lead. The American finished 32nd in the 31.9km time trial on stage 4 after enduring a very slow bike change which cost him almost a minute on the road.
