Ralf Rangnick doesn't consider Mason Greenwood to be a regular for Manchester United as the youngster clashes with Cristiano Ronaldo.
The rising star has been on the fringes since the interim boss arrived at Old Trafford despite being one of Ole Gunnar Solskjaer's first-team picks before he was sacked.
And the 20-year-old is believed to be 'upset' with his lack of playing time under the new manager.
El Nacional claims his grievances stem from his sudden reduction in minutes coinciding with Cristiano Ronaldo's arrival in the summer.
Greenwood is also believed to be frustrated by how Ronaldo has been fast-tracked into a leadership role inside the dressing room.
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This has reportedly led the United rising star to assess his options and consider a future away from Old Trafford.
It's believed Arsenal are keen on the England youngster, but the likes of Juventus and Barcelona are also keeping tabs on the situation.
The friction between Greenwood and Ronaldo has been lingering for some time.
The Portugal star questioned United players who were born after 1995, which includes Greenwood, before their 5-0 drubbing against Liverpool at Old Trafford, suggesting there is some unrest within the dressing room, particularly among the senior players.
As quoted by DAZN via The Telegraph, Ronaldo said: “I don’t mean only in football, this new generation since probably 1995 they are thinking different.
"The life, the football, the struggles, this has to come from inside of you. You have to accept some times that you don’t agree with."
The experienced forward is also believed to be annoyed at Greenwood's tendency to shoot rather than supplying him with a scoring opportunity when they have been paired together this season.
Greenwood considers himself good enough to be a regular in United's starting XI - he proved that under Solskjaer.
But the issue is that Rangnick doesn't, not yet anyway.
The German reckons the youngster needs to develop physically to reach that point as he praised the "massive talent" following his acrobatic finish against Young Boys in the Champions League.
He said: "I think today he also showed not only the quality because of that beautiful goal, but also the way that he set up the opportunity for Juan Mata was brilliant.
"He's a massive talent - left foot, right foot, good on the ball. Also the way that he set up the goal for Fred on Sunday, so it's about continuity.
"He has to develop physically but technically for his age he is a great player. My job is to develop him, to make an athlete out of him and if he manages to do that, he can become a regular player for this club."
