Manchester United forward Cristiano Ronaldo's relationship with Erik ten Hag has reportedly been frosty since the five-time Ballon d'Or winner questioned the manager's training methods.
The Portugal star stormed down the tunnel after refusing to come on as a late substitute in Wednesday evening's 2-0 win over Tottenham.
The forward was fined two weeks' wages and left out of the squad for the trip to Chelsea on Saturday evening.
The Athletic report that it was a disagreement over training methods that initially strained the relationship between the pair.
The report claims that Ronaldo's influence on his colleagues means that any comments questioning the manager's coaching ability could have sparked a rebellion.
Manchester United are reportedly willing to let Ronaldo leave in January, however Ten Hag wants to keep the 37-year-old until the end of the season.