Great Britain's Joanna Rowsell has withdrawn from this weekend's track cycling World Cup in Mexico.
Rowsell, 25, will instead focus on conditioning training with the aim of improving her chances at the London round of the series from December 5-7.
European champions Katie Archibald and Laura Trott lead a strong British squad for the opening round in Guadalajara.
Nine members of the 16-strong squad won gold medals at last month's European Championships in Guadeloupe.
The men include individual pursuit champion Andy Tennant and 1km time trial gold medallist Callum Skinner.
Revised GB squad:
Men's sprint: Matt Crampton, Phil Hindes, Jason Kenny, Callum Skinner
Women's sprint: Danni Khan, Jess Varnish, Vicky Williamson
Men's endurance: Steve Burke, Mark Christian, Ed Clancy, Jon Dibben, Andy Tennant
Women's endurance: Katie Archibald, Elinor Barker, Ciara Horne, Laura Trott