Noussair Mazraoui was slammed by Lee Dixon after a comical blunder during Man United's 2-1 win over Leicester on Friday night.
The Red Devils escaped Old Trafford with a spot in the fifth round of the FA Cup, thanks to a last-gasp winner from Harry Maguire.
But the road to victory was far from smooth sailing, and Mazraoui's blooper was one of many bumps on the way to United's fourth win in five games.
Former Arsenal hero Dixon was astounded after the Moroccan fluffed a throw-in and was whistled for a foul throw.