Paul Pogba left Manchester United in 2012 but returned to the club after a four-year stint with Juventus. © AFP After David de Gea, Paul Pogba is arguably Manchester United’s most important player. However, in his first stint with the English giants, as a 19-year-old in 2012, Pogba due to a lack of opportunities and trust from first-team boss Sir Alex Ferguson left Manchester United to move to Italian club Juventus. Former Manchester United midfielder Darren Fletcher has revealed that, in 2012 under Ferguson, Pogba was not disciplined enough to play in central midfield for the reserves, never mind the first team.”The first time I spent out with my illness I did a spell coaching the reserve team when it included (Paul) Pogba, (Jesse) Lingard, (Ravel) Morrison and we played him higher up the pitch in attacking areas,” Fletcher said on Sky Sports’ Monday Night Football coverage of Huddersfield’s win over Fulham.”We felt like he was the one who would win us game, coupled with the fact he has ill-disciplined in the middle of the park.”It goes back to a famous game when we felt like he left off the back against Blackburn. Paul was on the bench and the…