Mathieu van der Poel broke a wrist in a mountain bike race in the Czech Republic at the weekend, and is a doubt for the Criterium du Dauphine, his team said on Monday.
The Criterium, on June 8-15, has attracted a top-drawer line up with Tadej Pogacar, Jonas Vingegaard and Remco Evenepoel all signing up in preparation for the Tour de France in July.
Van der Poel is the top one-day racer in road cycling, but prefers mountain bike and cyclo-cross, alternating the disciplines.
Van der Poel's team Alpecin will be targeting stage wins and the green points jersey at the Tour de France with sprinter Jasper Philipsen.
"The injury will be subject to continued and intensive medical evaluation throughout the week," Alpecin said on Monday. "Which may offer greater clarity regarding his programme and the potential for participation in the Criterium du Dauphine."
Van der Poel crashed out of the Olympic mountain bike race at the Tokyo Games in 2021, suffering niggling hip and back injuries that blighted the following season.