The 37-year-old striker made a number of claims against the club, the Glazer family, manager Erik ten Hag, former players and much more besides during a lengthy discussion on his situation at Old Trafford.
On Friday morning, United issued a cryptic response alluding to “appropriate steps” being taken.
A club statement read: “Manchester United has this morning initiated appropriate steps in response to Cristiano Ronaldo’s recent media interview.
“We will not be making further comment until this process reaches its conclusion.”
There have been calls from some quarters for the club to sack or sell Ronaldo for his remarks.
The player most recently insisted that being called up as a late substitute while the team was winning was a sign of disrespect.
He also claimed: “I felt betrayed. Honestly, I shouldn't say that ... but, listen, I don't care, I'm always... People should listen to the truth.
“Yes, I feel betrayed and I feel that some people don't want me here, not only this year but last year, too.”