Italian rider Sonny Colbrelli collapsed after taking second place in the first round of the Volta in Catalonia.
The Bahrain Victorious rider is being treated at a hospital in Girona, Spain, where the team says his condition is “stable”.
Colbrelli, 31, was examined by medics behind screens near the finish line before being taken to hospital by ambulance.
“Sonny Colbrelli collapsed and received medical treatment,” the team said in a statement.
Colbrelli narrowly lost to Bike Exchange’s Michael Matthews in a sprint at the end of the first stage to Sant Feliu de Guixols.
31-year-old European champion Colbrelli missed Saturday’s classic “monument” Milan-San Remo due to bronchitis.
Colbrelli won last year’s classic Paris-Roubaix monument – his biggest career win to date, reflecting a significant improvement in form.
He also placed second in the traditional spring road cycling classic Omloop Het Nieuwsblad.