Stoke City defender Bruno Martins Indi has suffered a head injury in Saturday's 2-0 home victory against Burnley.
Boss Mark Hughes is worried that the 24-year-old Portugal-born Dutch international may have fractured his cheekbone.
"The fear is that it may be a crack in a cheekbone," Hughes told BBC Stoke.
"He's got a big bang on the side of his cheek. We'll have to wait and see as the swelling comes down."