I'm not saying Liverpool can't play well without Salah, but with Salah, Liverpool will certainly be better able to maximize their attack patterns. Salah is an icon for Liverpool so far, so when the team plays without his presence there is something different.
The strength of Liverpool's attack line will not be completely good without Salah, especially in tough matches Salah is really needed. I know Nunez, Diaz and Gakpo can play well, but Salah is a player who can bring a lot of change to Liverpool's attacking game.
With Salah's absence, Liverpool has still not lost a game. There is a hot player and finisher for the club that is filling well into the shoes of Salah, Diogo Jota who has scored goals for Liverpool. He is fast and very good on the ball, his goal scoring ability may be the advantage for Liverpool because even when he does not play a full game, he can come in, play a few minutes and still deliver the results expected from him. On the other side, Chelsea are also now scoring with the chances they create, so there is much chance that Liverpool goalkeeper will also be tested a lot.
Salah's absence has affected the teams performance no doubt but I feel his gap has been filled up given to the fact the frontliners currently in Liverpool are converting chances, Diaz, Gakpo and Diogo jota are doing excellent job, if that there where more loses and draws ever since salah went to the AFCON, we would have concluded to say he's absence has created a lot of gap, but so far liverpool are doing perfectly fine.
Liverpool Chelsea is a big game, so the both clubs will definitely bring out their best, so we might be seeing a lot of good football from the Chelsea side because they are more less the under dogs in at encounter, and they would want to prove themselves that they are the pride of LONDON even though they will be visitors at anfield.