Although Liverpool did not manage to win any of their first two games, their performances were still quite superior and dominant. So I don’t really think Nunez absence will create a space in that attack. They have Firmino, he is now fit after missing the home game against Crystal Palace and will likely start against Manchester United so they will have that attacking presence and they’d fancy securing their first win.
Liverpool did play fairly well in their last two games against Fulham and Crystal Palace, but they were very far from being dominant, if you watched their first game against Fulham, they didn't play too well in the first half, Fulham were arguably the better team in the first half, though Liverpool played a much better second half, but not entirely dominating; same thing against Palace, though i guess it is difficult to break down teams that set out to defend from the get-go.
Having said that, if Liverpool are going to compete for the title this season, then they must improve on their performances, they have not been at their very best lately, and they can't alllow City to run clear of them, or else the League could be in City's hands yet again quite early. Liverpool will definitely miss Nunez, i don't know if Firminho is fully fit, and with the other injuries they have, they'd need more players to increase their squad depth, but sadly Nunez is going to miss a couple of games for his misconduct.