Crystal Palace captain Marc Guehi is sidelined with a foot injury for the Brighton match, though midfielder Adam Wharton returns to the starting XI after an illness.
Glasner said his skipper is unable to walk and will also miss out for England during the international break.
“A knock on his foot,” said the Palace. “The bone bruised, he can’t even walk at that moment.
“In the last few days he was on crutches. That’s why he couldn’t play as I expect.