Eberechi Eze paid his former club QPR a visit on Saturday in a move which may not go down well with his current side Crystal Palace.
Palace boss Roy Hodgson this week made it clear to his players that no further breaches of Government coronavirus guidelines will be accepted after captain Luka Milivojevic breached the rules on New Year's Eve.
Milivojevic issued an apology on Wednesday after his household mixed with Fulham forward Aleksandar Mitrovic and his family.
It is understood Eze was a guest of QPR, with the visit approved by the FA subject to social distancing protocols being followed.
QPR boss Mark Warburton said: "I've no idea whether he broke protocols or not. You'd have to ask our health and safety officer because that's above my pay-grade.
"I want to talk about the game. What other players do in their own time, I can't comment on that. It's not my area of expertise. Far from it."