Reece James hobbled off in the first half against Brighton.
Andreas Christensen picked up a knock in the first half but managed to stay on the pitch until half-time.
This game is the second in a row in which Chelsea had to make two forced substitutions, and Thomas Tuchel is understandably frustrated.
"We have two injuries again," Tuchel told Amazon Prime after the Brighton game.
"We played with players who would normally be out after 60 minutes. That's it."
"There is no prognosis. It's a hamstring injury," he said about Reece James' injury.
"We simply have too many players coming back from long injuries and Covid. The injury of Reece James was a huge blow.
"Andreas was one of the top players on the pitch and at some point, it is too much against a Brighton team with nothing to lose."
Tuchel has also confirmed that Christensen has suffered a back injury.
