Police have confirmed they are investigating claims that Sunderland winger James McClean received death threats after deciding not to wear a Remembrance Day on his shirt at Everton last weekend.
McClean, 23, is believed to have received threats on Twitter in the days following the decision, and police have said the matter is being investigated.
Republic of Ireland international McClean received a mixed reception from the travelling support when he came on as a substitute as Sunderland won at Fulham on Sunday.
Northumbria Police said: "Police are carrying out inquiries following a third party report of threats made on social networking sites. Officers have spoken to Sunderland AFC, and inquiries are ongoing."
Speaking to reporters after his side's win in London, Black Cats manager Martin O'Neill said McClean had received threats but backed him to deal with the situation.
"James will deal with it [the booing]," he said. "I think it is to do with the issue last week. It's a free choice in this world.
"James has lived with a lot of things - he's getting death threats too now, so that doesn't help."
Information from the Press Association was used in this report