The Croatia midfielder has suffered a minor setback, and could now be a doubt for Wednesday's Champions League semi-final second leg against his former club Real Madrid.
Toni Rudiger will also miss the Fulham clash with a minor knock.
Fulham manager Scott Parker has no new injury concerns to contend with as his side head to Stamford Bridge on Saturday looking for their first victory at Chelsea since 1979.
Captain Tom Cairney has been stepping up his recovery from a long-term knee injury which has kept him sidelined since December, and Parker is hopeful the midfielder will be able to play some role before the end of the season, although Saturday's clash will come too soon.
Terence Kongolo remains sidelined for the remainder of the season, in what has been the latest in a long list of injuries.
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.
Provisional Fulham squad: Areola, Aina, Andersen, Adarabioyo, Robinson, Decordova-Reid, Anguissa, Lemina, Lookman, Maja, Cavaleiro, Fabri, Hector, Ream, Odoi, Bryan, Onomah, Loftus-Cheek, Mitrovic.