Cristiano Ronaldo was livid to discover Ralf Rangnick had axed him from the Manchester United starting XI to face Manchester City, according to reports.
The legendary striker, 37, was notably missing from the squad for Sunday's derby and was not present at the Etihad as United were thrashed 4-1 by their local rivals.
It was only the second Premier League game Ronaldo had missed all season since his transfer from Juventus last summer.
Rangnick explained Ronaldo's absence by saying he had suffered a recurrence of the hip issue which prevented him from featuring against Aston Villa in January.
"Cristiano had some problems with his hip flexor on Friday and since then, he didn't train," the Red Devils interim manager said ahead of kick-off.
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Even though Rangnick claimed club physios ruled him out, Ronaldo was furious to learn he would not be lining up to face City, according to The Sun.
The five-time Ballon d'Or winner then decided to fly to his native Portugal, leaving his teammates shocked when he did not emerge at The Lowry Hotel on the eve of the derby.
The rest of the squad also felt Ronaldo's absence sorely on matchday as they believed they could have benefitted from his presence in the dressing room, even if he was not able to play against the league leaders.
Adding to Rangnick's woes in the wake of the humbling defeat, the report adds it is unclear whether Ronaldo will report for training, raising questions of his future at United.
The Real Madrid legend is due back at the club's Carrington base on Tuesday after the squad was given the day off on Monday.
Rangnick requires his players to rehabilitate from injuries close to home rather than jet abroad for home comforts.
Speaking after the match, the German insisted once again Ronaldo is injured after club legend-turned-pundit Roy Keane questioned whether there was more to the issue than meets the eye.
"I have to believe our medical department," Rangnick said. "Our doctor came to me on Friday morning to say Cristiano couldn't train because of some problems with his hip flexor and the same on Saturday."
In Ronaldo's absence, United were dismantled with Kevin De Bruyne and Riyad Mahrez each scoring twice for the hosts.
Jadon Sancho's excellent first-half strike, which briefly drew the Red Devils level, was one of the very few positives for Rangnick's men.
It remains to be seen whether Ronaldo - United's top scorer this season with 15 goals in 30 games - will return to contention ahead of Saturday's clash with Tottenham.
