I wouldn't write Chelsea off to make the top 4!
Like us they don't have the distraction of European Football and their disappointing recent results have come whilst Terry has been out injured. Even at 35 Terry is a huge influence to that Chelsea team.
As impressive a start we've had I still feel we are severely lacking in adequate backups when the inevitable injuries and bans pop up. Milner has done well at LB but if he gets injured/banned we've got the calamity that is Moreno as back up! If Clyne gets injured/banned we don't have anything half decent to fill his boots. The CB situation is also precarious because if Matip (who has been our most influential so far in defence) gets banned/injured I don't trust Klavan to be consistent and the likes of Gomez is starting from scratch, with the Lucas trial already done and dusted! I also believe that if we are up there come January, FSG won't want to spend because they'll believe we have enough adequate players and judging by the summer window they won't want to pay January prices because they'll be even more inflated!
We'll do well to get 4th as we tail off due to not having adequate back up players when we feel the pinch, because FSG don't want to spend what is required!
Most of the top clubs will struggle if they lose important players, with maybe the exception of Man City. If your going to be hypothetical about Liverpool and injuries then you have to do it with the other sides.
What if Ibrahimovic, De Gea, Bailly or Pogba get injured for Man Utd? Then they are back to where they were last season.
What about Hazard or Costa getting injured for Chelsea? They've fallen apart without John Terry already!
I think Arsenal would struggle if they lost Sanchez, Koscielny or Ozil for any period of time as well?
You could use the same argument for City although they have the strongest squad, but say De Bruyne and Aguero both got injured, they are impossible players to replace.
Injuries are part of the season and will affect all clubs, not just Liverpool.