Bath City's Alex Russell was kept in hospital overnight after collapsing on the team bus.
The 38-year-old started feeling unwell during the journey up to York and was taken away in an ambulance.
"Near our stop in Wakefield he became unconscious," manager Adie Britton told BBC Somerset before the game.
"He's had some migraines before and, if it is a migraine. then it is very, very severe because he's got some form of breathing difficulties."
Britton added: "Apparently the tests they've carried out on him are all clear and he's now semi-conscious.
"Quite obviously our thoughts are with him at this time and we hope he's OK."
Russell, who has made 573 career appearances, counts Rochdale, Cambridge, Torquay, Cheltenham, Bristol City, Exeter and Yeovil among his former clubs.