Manchester United have been told the key reason behind their struggles since Sir Alex Ferguson retired in 2013.
Following on from the legendary United manager's retirement, the Reds have failed to win the Premier League. Their only major silverware has come in the form of cup competitions.
United suffered a disastrous campaign last year under Ole Gunnar Solskjaer and Ralf Rangnick which ended in their lowest ever points tally in the Premier League. In the summer, the Reds hired Erik ten Hag and although there was signs of improvement in pre-season, the same frailties from the previous regime scuppered opening day success.
