Manchester United manager Erik ten Hag has a mixed record with substitutions in recent matches. When you look back to Manchester United’s 4-3 win over Liverpool, one of the aspects Erik ten Hag got right was that he nailed his substitutions. United are winless in the three games since, and it’s been a mixed bag. He certainly seemed to get it right against Brentford, when substitutes Casemiro and Mason Mount combined to put the team ahead. The two subsequent games against Chelsea and Liverpool the manager has got it wrong. And you can pinpoint the same error. READ MORE: Who is Alejandro Garnach…