Darwin Nunez surely will serve his suspension after collecting a red card against Crystal palace and Liverpool already have as many as eight absentees due to various injuries. So it’s an advantage for Manchester United as they will not be facing a full strength Liverpool squad, so their chances of taking any points from the game look slim. It’s going to be a tough one for Klopp. Although Firmino is fit so I expect him to start and Liverpool will want to grab their first win of the season in Old trafford.
Getting a red card when he still needs adaptation in a new league is certainly a bad achievement for Nunez, losing Nunez is a loss for Liverpool and I think maybe Klopp will punish Nunez for his actions in the match against crystal palace yesterday apart from a 3 match suspension due to a card red, but I think losing Nunez for a while will not have an impact or even weaken Liverpool in the match against Manchester United later, because after all Klopp is a coach who is able to make changes to game strategies quite well and most likely Klopp will do a little improvisation to cover the lack of attackers in the againts manchester united match later if firmino is still not fit.