Given the lack of recovery time, and also given that Southampton are, while strong, also not a rival, I'd be amazed if we played our 'best' team.
Looking at who started Norwich and minutes played etc we've got something like:
Origi, Keita, Milner, Oxlade, Gini, Mane and Robbo (subbed off), TAA
- all relatively fresh.
Almost certain that Origi and Mane start, with two of Keita/Gini/Oxlade/Milner also very likely, TAA + Robbo is nailed on.
Gomez, Salah, Hendo, Fabinho, VvD all played Norwich and the full 120, right? So we've got to be looking at resting at least some of these - no chance of both Hendo and Fabinho starting, I'd say, Gomez and Salah must also be likely candidates to start on the bench.
Shaqiri and Bobby are slightly odd in that the latter is fresh but rarely played without a change of system, and the latter would seem nailed on to start but hasn't Klopp already said he wasn't supposed to play at all against Chelsea?
So my guess is something like this:
Origi Bobby Mane
Keita Gini
Hendo
Rob VvD Matip TAA
But there's an outside chance of something like this:
----------Origi
Mane Lallana Shaqiri
Gini Milner
Robbo VvD Matip TAA
The latter would make most sense from fitness perspective, but seems unlikely that we'll rest 2 of the front 3.
It'll be interesting to see, though.