AC Milan make one change from the 11 that began the 2-0 home win against Juventus at the weekend as Rade Krunic comes in for Tommaso Pobega.
That means forward Olivier Giroud, who won the Champions League, Europa League and FA Cup during a four-season spell with Chelsea, starts against his former team, while ex-Chelsea defender Fikayo Tomori also plays.
Ex-Liverpool striker Divock Origi is among the substitutes.
AC Milan XI: Tatarusanu, Hernandez, Tomori, Gabbia, Kalulu, Tonali, Bennacer, Leao, Diaz, Giroud.
Subs: Mirante, Jungdal, Toure, Dest, Coubis, Pobega, Messias, Rebic, Origi.
Graham Potter makes six Chelsea changes from the side that began the 3-0 win against Wolves on Saturday.
In come Thiago Silva, Ben Chilwell, Reece James, Mateo Kovacic, Raheem Sterling and Pierre-Emerick Aubameyang and out go Cesar Azpilicueta, Marc Cucurella, Ruben Loftus-Cheek, Conor Gallagher, Christian Pulisic and Kai Havertz.
Chelsea XI: Arrizabalaga, Koulibaly, Chalobah, Silva, Chilwell, James, Kovacic, Jorginho, Mount, Sterling, Aubameyang.
Subs: Mendy, Bettinelli, Azpilicueta, Cucurella, Zakaria, Loftus-Cheek, Chukwuemeka, Pulisic, Broja, Havertz.