Trek-Segafredo confirmed on Thursday that Gianluca Brambilla will miss Saturday's Strade Bianche and the forthcoming Tirreno-Adriatico stage race (March 7-13) in Italy as he is suffering from pneumonia.
The 30-year-old Italian was due to be one of the American team's hopes on the famous white roads of Strade Bianche in Tuscany, having placed third in the race in 2016.
Trek reported earlier in the week that Brambilla would be out of the race due to a fever, and was replaced in its line-up by Nicola Conci.
However, Conci has also fallen ill and so his place will be taken by Laurent Didier.
"Team doctor confirms @glbrambilla has pneumonia," Trek-Segafredo said via Twitter. "We will update here on his recovery process, but unfortunately no @StradeBianche and no @TirrenAdriatico for him. We wish you a speedy recovery, Gianluca!"
Brambilla joined the Trek-Segafredo team from Quick-Step for 2018. He won stages of both the Giro d'Italia and Vuelta a España in 2016.
Other teams have also been forced to make roster changes for Strade Bianche and Tirreno-Adriatico as riders have fallen ill or become injured.
Richie Porte is a high-profile withdrawal for BMC Racing from Tirreno-Adriatico, as he suffers from a respiratory infection.
The race had been one of the Australian's targets for the season.
With poor weather forecast for this weekend in Italy, there may be further withdrawals ahead of the races.
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