Arsene Wenger demanded an explanation from Granit Xhaka on Wednesday after the Arsenal midfielder was accused of racial abuse at Heathrow Airport.
Manager Wenger spoke to Xhaka at the club's London Colney training ground.
It had emerged earlier that Xhaka was questioned by police for allegedly calling a British Airways employee a 'f****** white b****' during a row on Monday night.
The Arsenal manager wants to establish exactly what happened at Terminal 5 before making a decision on any punishment, though it is understood that the Switzerland star has been reminded of his responsibilities as an Arsenal employee.