It has been reported, sympathetically, that he’s not good at training (Toney said this while self-deprecatingly saying he was worse). If you went to Stoke, you’ll have seen Fosu run around very energetically but somewhat like a headless chicken entirely independently of team shape or strategy. Most fans love Fosu for his energy and unpredictability (he’s clearly got talent) and praised some nice recoveries while forgetting that he’d lost the ball in the first place. From that, I can see why TF, who has had an approach of meticulous preparation and planning with very clear individual and team roles as being the way to ensure that as a team we overcome broadly being worse individually in pretty much all positions than pretty much every opponent and are nevertheless able to compete. Throwing on a wildcard who might snatch something with a moment of genius or might give something away by regularly not being where he’s meant to be is not going to fit. Even if you think Ghoddos is a worse performer, he has manfully done what is asked of him even when often played out of position and apparently not ever really being given his preferred free role. Fosu would equally enjoy such a free role but interprets every role he’s given as a free one. No need for any falling out,
Maybe TF ought to be less rigid but he has worked hard on his strategy as have most other players. They’re not all at all perfect at it but with say Sergi, who despite being my favourite player, I’d have been very sceptical about having the focus to play at all convincingly as a RWB in the PL, you can see how hard he is trying to do just that and rein in instincts to play more as an individual. At this level it is essential unless you are Ronaldo good and even he hasn’t turned Man U into an inexorable winning machine. That’s why Benrahma has had to do all that work learning how to do defensive shape and positioning, sometimes looking in mental anguish at it last season but now being a major part of his team and also contributing with goals and assists.