Kovacic has been out of action with a hamstring problem and just failed in his bid to be fit for Saturday's FA Cup final, where Leicester defeated Chelsea 1-0.
Christensen has been dealing with a leg tendon issue but could strengthen the Blues' options in defence.
Leicester will be without defender Jonny Evans.
The Northern Ireland international limped off during the first half of Saturday's final with an ongoing heel problem.
Chelsea provisional squad: Arrizabalaga, Rudiger, Alonso, Christensen, Jorginho, Silva, Kante, Abraham, Pulisic, Werner, Caballero, Zouma, Mendy, Kovacic, Giroud, Mount, Hudson-Odoi, Chilwell, Ziyech, James, Azpilicueta, Havertz, Palmieri, Gilmour, Anjorin.
Leicester provisional squad: Schmeichel, Ward, Jakupovic, Fuchs, Fofana, Soyuncu, Pereira, Daley-Campbell, Castagne, Thomas, Choudhury, Tavares, Ndidi, Tielemans, Maddison, Mendy, Amartey, Praet, Perez, Albrighton, Vardy, Iheanacho.