Red Devils boss Erik ten Hag brought Weghorst in on a loan deal in the January transfer window to add to his attacking options following the departure of Cristiano Ronaldo.
His impact has so far been limited and has yet to open his Premier League account for Manchester United.
Weghorst completed the full 90 minutes for Manchester United in their 3-0 win over Leicester City on Sunday, but Keys thinks he is a drag on the Red Devils.
The veteran anchor feels that when Weghorst is in the side, Manchester United are effectively playing with ten men.
“You’re playing with ten most weeks if he’s in”, Keys said of Weghorst on beIN SPORTS.
“I mean, he doesn’t do enough to justify a starting place does he?
“Come on, let’s be honest.”
Manchester United have two key games coming up, with Barcelona in the second leg of their Europa League tie on Thursday night at Old Trafford, followed by the EFL Cup final against Newcastle United next weekend.
It remains to be seen if Weghorst starts in either game.
