Great Britain's Jonathan Tiernan-Locke has been ruled out of Sunday's elite race at the Road World Championships.
The 28-year-old 2012 Tour of Britain winner, who is replaced by Luke Rowe, tweeted: "Sorry I had to withdraw, don't have the form to help the lads."
Tour de France winner Chris Froome will lead the eight-man British team, which also includes Sir Bradley Wiggins and Mark Cavendish.
Wiggins took time trial silver in Tuscany, Italy on Wednesday.
Rowe, 23, who won stage one of the Tour of Britain in 2012, tweeted: "Worlds this Sunday, looking forward to having a dabble and do what I can to help Froome. Always good to get a ride in the worlds."
Geraint Thomas, Ian Stannard, Steve Cummings, and Josh Edmondson make up the rest of the Britain team.