West Ham will look into the events that led to West Brom midfielder Jake Livermore’s confrontation with home fans at London Stadium on Tuesday.
Livermore was substituted in the second-half of his side’s 2-1 defeat.
The England international then got involved in a heated exchange with some West Ham supporters and needed escorting down the tunnel.
West Brom manager Alan Pardew said he did not know what prompted Livermore to react as he did.
“Obviously you don’t want to see a player in the crowd,” said the Baggies boss.
“There’s no way he’s going in the crowd – because I know him, he’s a great lad – unless he was provoked severely. That’s all I know.
“I haven’t had a chance to talk to Jake. I’ll speak to Jake and we’ll go from there.”
West Ham manager David Moyes said he did not see the incident, but added: “I didn’t know about it, but I’ve been told something happened.”