Chris Smalling and Klaas-Jan Huntelaar were both taken to hospital after they clashed heads during England's 3-2 defeat to the Netherlands at Wembley Stadium on Wednesday.
The duo accidently collided in the second half as Huntelaar headed the visitors into a 2-0 lead.
"Chris went to hospital. I spoke with him and he was conscious, but he split his head open. Our thoughts are with him and I am hoping that he will be fine," said England caretaker coach Stuart Pearce.
After goals from Gary Cahill and Ashley Young drew the hosts level, Arjen Robben's late strike sealed the win for the away side.