Manchester United say they are taking "appropriate steps" after Cristiano Ronaldo's interview in which he said he was "betrayed by the club".
The Portuguese forward said he had "no respect" for manager Erik ten Hag and is being forced out of Old Trafford.
"Manchester United has this morning initiated appropriate steps in response to Cristiano Ronaldo's recent media interview," said a club statement.
The club will not comment further until "this process reaches its conclusion". After a wide-ranging interview with Piers Morgan for TalkTV, the future of Ronaldo at Man Utd is in doubt.
The 37-year-old Ronaldo will captain Portugal at the World Cup in Qatar, with their opening Group H game against Ghana on Thursday.
He has not played because of an unspecified illness since he captained United in their 3-1 defeat at Aston Villa on 6 November
Ronaldo was dropped for the Premier League game at Chelsea last month by Ten Hag after refusing to come on as a substitute against Tottenham three days earlier.
The club are refusing to say what precisely 'appropriate steps' are but cancelling Ronaldo's contract and/or taking legal action are likely to be high on the list.