Enzo Fernandez and Mykhailo Mudryk were both absent from Chelsea squad for the 2-0 defeat to Brentford on Saturday at Stamford Bridge.
Noni Madueke and Nicolas Jackson replaced the duo in the starting XI for the game against Brentford.
“Enzo and Misha felt something in training yesterday,” Chelsea boss Mauricio Pochettino told reporters.
“Small muscle injuries for them both. We hoped they would be okay to be in the squad but they aren’t quite ready. Neither of them are big issues but we didn’t want to take risks.”