433 wont work with our current personel, you either go the pep way and have the two in front of the base taking turns to support the attack, who are good passers, buying into the ethos, the team comes first or the way SPurs are going with three midfielders who are industrious and can pass, with either two of Sissoko or Winks who can sit a little deeper, all three being fairly athletic, alternatively the Liverpool way, where you have just three work horses, who's role is just to win possession and recycle the ball.
The truth is what Ole should of done towards the end of last season is give Fred a run of 5 to 10 games straight, playing Fred in the Europa league won't help his development in the league, as the pace in europe tends to be slower, with the run of 5 or 10 games last season, would of allowed Fred to get to grips with the league a little better.
Then come this season Fred and Mc T would be the base, Pogba behind Martial, James and Rashford rotating on the left, and Linguard and Rashford rotating on the right.
We actually played 4231 during the honeymoon period, with Pogba behind the striker with Martial on the left and Linguard on the right, the reason is was successfull is because of how industrious Herrera was.
All that needs to happen going forward is give Fred a run of games, push Pogba forward, but he needs to help the team and press, cut out the fancy dan stuff and focus on what he is good at making passess.