I think the book markers are considering the Liverpool Manager doing that already that's why the odd of the Liverpool team to when is higher than that of their opponent PSG, Liverpool has already qualified for the next round of the champions league the manager will have to give some of the players a chance start tonight while Mo Salah and some regular starters may be rested or maybe used in the second half. I don't know about the financial difference between the 1st and the 8th position but Liverpool can still use the players to win Psv despite playing from away.
Liverpool played well in Premier League and Champions League, and with this last unimportant match for them, they have reasons to use squad B or C in this match. They have more important matches in Premier League to focus on at this moment. When Champions League returns with knock out matches, Liverpool will have to use their main squad again, but it's not their situation now.
Mohamed Salah doesn't need to play in this match and Liverpool needs him for many more matches in Premier League and Champions League at later phases too.