World champion Peter Sagan says he is unsure if he will defend his title in Qatar in October.
Asked if he would travel to Doha for this year's World Championships, Sagan said: "We will see."
The Slovakian, speaking after finishing third overall in the Eneco Tour, added: "I still have to think about it. It's been a long season."
His absence could help British 2011 world champion Mark Cavendish, who would be suited to the flat course.
Sagan, who rides for Saxo-Tinkoff, added: "I'm tired. I have a lot of things to do. I'm happy the season is almost finished."
The UCI Road World Championships take place between 9 and 16 October in Doha.