Australian Richie Porte was forced to withdraw from the Tour de Romandie on Thursday after suffering with stomach problems.
The BMC man picked up the virus overnight after Wednesday’s truncated first stage.
“He has developed some gastro-intestinal problems and a fever overnight,” explained his BMC team doctor Dario Spinelli.
“He is showing signs of a virus and has lost his appetite.”
After the prologue and first stage, Porte was 37 seconds behind surprise overall leader Ion Izagirre of Spain.
“Of course it’s disappointing to stop, but I trust the doctors,” said Porte.
The 31-year-old has had a stop-start season so far since joining American outfit BMC from Team Sky, finishing second on the Tour Down Under and third in the Paris-Nice.