Salah suffered a knee injury ahead of the international break after being on the receiving end of a shocking tackle by Leicester City midfielder Hamza Choudhury.
The 27-year-old is set to be back the starting eleven against Genk in the Champions League after being involved in the Reds' open training session on Tuesday and traveling with the squad to Belgium.
Salah's inclusion will be a big boost for Klopp, whose side were clearly missing him in attack against United on Sunday.
LIVE @ChampionsLeague training from Melwood 💪
— Liverpool FC (@LFC) 22 October 2019
However, the Reds will be without key defensive duo Alexander-Arnold and Matip, who both missed training and remained at Melwood to recuperate.
On the duo's absence, Klopp said: “Trent is ill and Joel is not ready.
“It is just a little thing which usually settles in the two weeks [Matip] had; it did, but then it came up after the United game and so now we just have to make sure this time it settles finally, that’s all.
“It is not a massive injury, it’s just a bit annoying for him and he cannot do it [face Genk].
“Trent got ill overnight; hopefully he can recover quickly, but for tomorrow there was no chance.”
Meanwhile, Xherdan Shaqiri is also sidelined for the fixture after travelling back to Switzerland for treatment on an ongoing calf injury.
Salzburg host Napoli at the same time on Wednesday night, with the Reds possibly having the chance to go above the Serie A side in the standings.