Casemiro, McTominay, Eriksen, Mount, Bruno, Mejbri, Mainoo.
That's 7 midfielders for 3 positions, we will not move for another midfielder if we dont sell McTominay.
So 5 midfielders for 3 position...you can't realistically count Hannibal and Mainoo (they are babies in the professional game)
Casemiro and Bruno will start every week when fit and available (or not suspended).
Eriksen and Mount will be rotated in their position depending on who is in the better form at that moment in time.
I personally don't see Mejbri or Mainoo breaking into the team this year. Fans always get carried away in preseason with younger prospects. When push comes to shove in the league, I think we'll more than likely play it safe and bring somebody else in. They may get a small number of minutes here and there, but that'll be extremely limited.
This then leaves the question marks around players like Fred and McTominay. VDB is already gone, in my eyes. It's a case of whether we can upgrade on Fred and McTominay and get in players who are better than them and who can be trusted to come into the side and either offer us something different, or provide cover for when one of the 'main four' isn't available.
This all implies that everyone will be fit, which they won't be. If Casemiro picks up an injury that rules him out for x amount of time, we need cover for that position.