If only one player like Nunez gets a red card at Liverpool. So Liverpool will easily put other players in Nunez's position even though the player's potential is slightly different from Nunez. And I think Liverpool will not be so difficult to face the game that will take place at home to Manchester United. Liverpool also know that Manchester United will try to win the game at home to get points after failing to get points twice in the previous two matches.
I saw that the Manchester United players were under a lot of pressure to win the game against Liverpool. This match will be played at Old Trafford stadium so that Manchester United chances are big enough to secure 3 points. but they have to play more aggressively and concentrate because the opponent they face is liverpool which their squad is quite strong. Liverpool defense is quite good but their front line seems to have lost sharpness in their last two matches.