Concussed Katie Archibald has been withdrawn from Saturday's madison race after a bad crash at the Track Cycling World Championships in Poland.
British Cycling said Archibald had initially been deemed fit to continue after falling heavily in Friday's omnium event.
But overnight she "developed signs of concussion". Elinor Barker will now partner Neah Evans.
Barker won gold in the 10km scratch race on the opening day.
Read more on Archibald's condition here.