James McClean has had abusive packages sent to him at the Stoke City training ground.
Potters manager Gary Rowett has revealed the news and says it is over the Republic of Ireland international's refusal to wear a poppy.
McClean chooses not to take part in the poppy commemoration for deceased members of the British armed forces due to their role in The Troubles and, in particular, the Bloody Sunday massacre in Derry, McClean's hometown.
The 29-year-old was abused by fans at last week's Championship draw with Middlesbrough, and warned by the English FA for calling his abusers "cavemen" on social media.
He was joined in not wearing a remembrance poppy this year by Man United midfielder Nemanja Matic, whose Serbian village was bombed during a 78-day NATO campaign in 1999.
Rowett says Stoke have spoken to the Derryman about his response, which he describes as understandable but ill-judged.