Kovacic’s thigh injury meant he was unable to face former club Real Madrid and will again sit out this weekend.
Tuchel has plenty of options, though, and makes five changes following their triumph over Real Madrid with Billy Gilmour, Reece James, Marcos Alonso, Hakim Ziyech and Christian Pulisic coming in.
Timo Werner scored against Real Madrid and keeps his role in attack with Christian Pulisic and Hakim Ziyech in support.
Gilmour has been afforded a rare start in midfield with N’Golo Kante, while Reece James and Marcos Alonso play on the wings in a 3-4-3 formation.
Chelsea XI: Mendy, Azpilicueta, Christensen, Rudiger, James, Kante, Gilmour, Alonso, Ziyech, Pulisic, Werner
Subs: Arrizabalaga, Jorginho, Abraham, Zouma, Giroud, Hudson-Odoi, Havertz, Emerson Palmieri, Livramento
Chelsea provisional squad: Arrizabalaga, Alonso, Christensen, Jorginho, Silva, Kante, Abraham, Pulisic, Werner, Caballero, Zouma, Mendy, Giroud, Mount, Hudson-Odoi, Chilwell, Ziyech, James, Azpilicueta, Havertz, Palmieri, Gilmour, Anjorin.