I hope you're wrong. They will be motivated for sure but as recent history shows, they can fight against fatigue and the opponent if the opponent is not a good team, but when they are against a good team their tight schedule is killing them.
Lazio were defeated 6 times this season and look at the teams that won against Lazio :
H-Milan 1:5
H-Fiorentina 0:1
H - Roma 2:3
A- Inter 0:3
A- Atalanta 1:2
H - Udinese 0:1
All of these are top 6 teams + a mid-table team (i like using this term for Milan

)
Milan, Fiorentina and Udinese all won at Olimpico.
I have a good feeling about this match. I think we'll win.