Pittsburgh Steelers reserve quarterback Skylar Thompson suffered an alleged assault and robbery in Dublin ahead of a historic game in Ireland on Sunday according to local media.
The 28-year-old was briefly hospitalised with minor injuries after the incident late-Friday which happened when he was socialising, said the Irish Independent daily newspaper.
Thompson was "jumped and robbed" according to the NFL Network news-site.
"We are aware of a situation involving Skylar Thompson on Friday night in Dublin," Steelers spokesperson Burt Lauten said in a statement.
"We will have no further comment at this time as we are working with NFL security to gather more information regarding the incident," it said.
The Irish police are "making enquiries" into the incident, it told AFP in a statement without giving further details.
Thompson travelled to Dublin as an injured reserve player with a hamstring complaint.
The Steelers beat the Minnesota Vikings 24-21 in a historic first ever regular-season game in Ireland at Dublin's Croke Park stadium on Sunday in front of around 75,000 fans.