Milan make changes for their Coppa Italia quarter-final, bringing in Junior Messias and Brahim Diaz with Olivier Giroud, while Lazio look to Ciro Immobile and Sergej Milinkovic-Savic.
It kicks off at San Siro at 20.00 GMT.
You can follow all the build-up and action as it happens on the LIVEBLOG.
The tie will be decided tonight after 90 minutes, extra time or even penalties if needed.
The winner will go on to face Inter in the semi-final, which is the only round in the entire tournament to be played over two legs.
Milan are fresh from a huge Derby della Madonnina victory in Serie A thanks to the Giroud brace, and with Zlatan Ibrahimovic still out of action, the French veteran again leads the attack.
There are changes behind him, though, Franck Kessie returning to a midfield spot with Messias, Brahim Diaz and Rafael Leao fanning out.
Fikayo Tomori and Ante Rebic are only fit for the bench, with Simon Kjaer and Fode Ballo-Toure unavailable.
Lazio are still without injured Francesco Acerbi, while Pepe Reina plays against his former club.
Felipe Anderson and Mattia Zaccagni flank Immobile, with Milinkovic-Savic in midfield, Toma Basic stepping in for Luis Alberto.
Milan: Maignan; Calabria, Kalulu, Romagnoli, Theo Hernandez; Kessie, Tonali; Messias, Brahim Diaz, Leao; Giroud
Lazio: Reina; Hysaj, Luiz Felipe, Patric, Marusic; Milinkovic-Savic, Cataldi, Basic; Felipe Anderson, Immobile, Zaccagni