Manchester (United Kingdom) - Manchester United said on Friday the club have "initiated appropriate steps" following an explosive interview  by Cristiano Ronaldo that left his future at Old Trafford in doubt.

The five-time Ballon d'Or winner said he did not respect United manager Erik ten Hag and took aim at the club's owners, the Glazer family, during the 90-minute interview aired on TalkTV.

"Manchester United has this morning initiated appropriate steps in response to Cristiano Ronaldo's recent media interview," the club said in a statement.

"We will not be making further comment until this process reaches its conclusion."

Former United captain Gary Neville said on Thursday that the Red Devils have no option but to rescind Ronaldo's contract, which runs until the end of the season.

Ronaldo is not due back in Manchester until after his fifth World Cup in Qatar with Portugal.