Sunderland defender Billy Jones suffered a concussion during the 2-2 draw with West Ham United, David Moyes has confirmed.
The right-back was taken from the field at the Stadium of Light on a stretcher in a neck brace after falling awkwardly following a shoulder challenge from Arthur Masuaku late in the second half.
After a lengthy stoppage, Jones was carried from the pitch and subbed in the 88th minute, with 10 minutes of added-on time played.
He was dazed in the aftermath and was taken to hospital for checks but Moyes said the defender is "fine".
Sunderland confirmed on Saturday night that the right-back had been discharged from hospital.
Moyes said: "Billy has gone to hospital but he is fine.
"We think it was concussion, his head hit the ground. My first feeling was that it was his shoulder but from the dugout that is how it looked.
"They tell me it is his head and it is concussion. They think he passed out during the game but he is fine.
"He was conscious. They asked him a few questions and he was a bit dazed and didn't answer them quite right but they think he is okay."
Sunderland, nine points from safety with six games to play, are now not in action for 11 days when they travel to face Middlesbrough a week on Wednesday.