It’s hard to see a way back for the 37-year-old striker, who said he didn’t respect the manager Erik ten Hag and feels “betrayed” by the club.
The question now is whether Ronaldo can secure a January transfer after failing to leave for a Champions League club before the start of the season.
United were already planning their life without him before extracts from his interview began circulating on Sunday evening – but that process is set to be accelerated after his latest public show of dissent.
Ten Hag has already had to blame him for leaving a pre-season friendly early – and kicked him out of his squad last month when he refused to come on as a substitute against Tottenham.
Ronaldo displayed an element of contrition on social media later and held candid talks with Ten Hag before being welcomed back into the fold.
But these new comments threaten to be a final blow in terms of the relationship between the Portuguese World Cup striker and his manager.
“I don’t have any respect for him because he doesn’t show me respect,” Ronaldo told Piers Morgan Uncensored TV show.
“If you don’t respect me, I will never respect you.”
Ronaldo also claims there is an attempt to push him out of the club.
This comes despite the five-time Ballon d’Or winner’s desire to leave earlier in the year.
Ten Hag was reluctant to let him go in pre-season, particularly due to a lack of viable replacements within his squad or in the market. And that problem persists until January, when United’s pursuit of a new centre-forward will be further complicated by the typically inflated prices during the mid-season transfer window.
United’s recruitment team would prefer to do their business at the end of the season – and Ten Hag was ready to fit Ronaldo into his plans for the rest of the campaign, even after the incident against Tottenham.
The feeling at United on Sunday night was that Ronaldo’s actions would not be allowed to detract from the positivity generated by Alejandro Garnacho’s late winner in the 2-1 win at Fulham.
Yet the opposite is true – and the former Real Madrid and Juventus striker’s off-field behavior has too often been an unwelcome distraction during his four months in charge of Ten Hag.
The timing of the interview also ensures he will remain suspended at the club while the Premier League takes a break for the World Cup.
Morgan declined to confirm when it was conducted, which only adds to the impression that it was a premeditated and staged attempt to achieve maximum impact.
“The club will review their response once all the facts have been established,” United said on Monday.
“Our focus remains on preparing for the second half of the season and continuing the momentum, belief and unity that is being built between the players, coach, staff and fans.”
This statement, in itself, suggests that the club’s hierarchy was taken by surprise.
The interview could also be interpreted as a message to potential suitors – and Ronaldo will have to hope to show up more than in pre-season.
His reputed salary of around 500,000 pounds a week (587,000 USD) rules out the majority of clubs in Europe.
While Ronaldo’s desire is still to play in the Champions League, the number of possible clubs is shrinking further, with that competition now down to the last 16.
Another problem is his unconvincing form this season – with just three goals in 18 appearances.
A good World Cup could see interest in the veteran striker grow.
In terms of substitution, the picture is hardly any clearer for United than it was last window.
Red Bull Salzburg striker Benjamin Sesko was a serious consideration, but he signed a pre-contract with RB Leipzig, while Darwin Nunez was another target before joining Liverpool.
The pool of potential strikers was so small that United even explored the possibility of signing the veteran Bologna striker Marko Arnautovicwhich drew a furious response from fans.
There is an acceptance among elite clubs that there are very few emerging players of Manchester City’s Erling Haaland profile.
This was underlined by Bayern Munich and Barcelona, who both signed strikers in their 30s as they chased top scorers earlier this year.
Bayern have signed 30-year-old Sadio Mane after selling 34-year-old Robert Lewandowski to Barcelona. Meanwhile, 34-year-old Karim Benzema continues to lead Real Madrid’s attack.
Ten Hag hopes Anthony Martial can overcome the fitness issues that have plagued his United career and is trying to help Marcus Rashford become a prolific goalscorer.
He may have to rely on this pair until the end of the season at least, with Ronaldo’s comments surely signaling an acrimonious end to his time at Old Trafford.