I think we probably all agree that either Cork or Davis should come in for Mane or Long and revert to the shape that has served us so well so far. Main question is, which one comes in and which goes out.
If Davis is fit, I think it's got to be him and in this game I would start Long (offers more defensively) with Mane as an impact sub.
Forster, Clyne Fonte Alderweireld Bertrand, Wanyama Schniederlin Davis, Long Pelle Tadic