Police are investigating after a West Bromwich Albion player was hit by a coin thrown from the crowd.
Chris Brunt suffered a cut under his left eye as he was injured by the 50 pence piece which he claimed was thrown by his own team's fans.
West Brom lost 3-1 to Reading at the Madejski Stadium on Saturday.
Brunt could have been blinded by the assault, West Brom head coach Tony Pulis said, as the player declared it was the first time he felt "ashamed" of the team's supporters.
Brunt described how he had seen a young girl in the crowd and gone towards the fans to give her his shirt when he was hit.
He said the team's FA Cup fifth-round exit may have angered supporters but added that is no excuse for what happened.
The 31-year-old Northern Ireland international said: "Obviously there's some people in the front who were angry, understandably, because we didn't play well or get the result we wanted.
"But there's absolutely no excuse for that and no place for it in football. I've been here a long time. Obviously we all get our fair share of stick but to be hit with a coin by your own fans is absolutely disgusting."
He offered to meet the person who threw the money, and added: "I've been here a long time and I've loved my time here and that's the first time I've been ashamed of our supporters. A small minority obviously ruined it for the rest of the 4,000 who were there and paid good money for a day trip."
Pulis said: "We have seen an incident where a lad who has played over 300 games for this club could have had his eye out.
"He has a cut and it's not too far away from his eye - it's an inch away from striking him in his eye and if that happens we're talking (about) a very, very serious problem."
Former England captain Alan Shearer said the incident was "disgusting", while Harry Redknapp described it as "cowardly".
Police said they are treating the incident as an assault.
A Thames Valley Police spokesman said: "The incident will be dealt with as an assault and we will be working with West Bromwich Albion and Reading to resolve the issue and identify anyone involved."
The Football Association said it is also investigating.