There was no influence on Sadio Mane departure with Liverpool performance. I assess the absence of Diogo Jota, Thiago Alcantara, Konate due to injuries that have an impact on Liverpool because at the same time Liverpool also lost Darwin Nunez.
Jurgen Klopp certainly can't relax looking at the composition of his players when facing Manchester United even in the next few games such as against Newcastle who are good in 3 games.
Forget the defeat against Manchester United, and hopefully Liverpool can improve in their next match against Bournemouth.
Klopp should have good options for the next match especially regarding his main line-up selection. Darwin Nunez is unlikely to be available next week, so Klopp really has to prepare his replacement in the next match. Firmino wasn't really good, he wasn't in good form I think.