It was staggering that Louis van Gaal did not turn to Radamel Falcao as Manchester United were trailing 2-1 against Arsenal in the FA Cup quarter-final . The poor lad must be thinking : What am I doing here ? I know he is not the player United thought they were getting , but isn ’ t it down to the manager to get the best out of him ? Radamel Falcao ( second right ) was an unused substitute during Manchester United 's defeat to Arsenal . Michael Carrick ( right ) was brought on at half-time but Colombia forward Falcao was left unused . Goalscorers change games but instead they chased the match with Daley Blind and Michael Carrick , two sitting midfielders , on the pitch . Surely it would have been better to show greater intent by throwing on Falcao ? United never threatened Arsenal once Danny Welbeck put them ahead and it is Arsene Wenger 's side who have progressed to the semi-final at Wembley .
Radamel Falcao did not leave the bench as Arsenal beat Manchester United . Louis van Gaal brought on Michael Carrick , Phil Jones and Adnan Januzaj . Danny Welbeck , a former United striker , scored Arsenal 's winning goal .