Chelsea have been encouraged after Moises Caicedo missed Brighton's friendly with Rayo Vallecano on Sunday.
Caicedo had complained about a hamstring issue before kickoff.
Asked if the midfielder would train on Monday, manager Roberto De Zerbi said: "I don't know. If Moiss leaves, we will find another important player. If Moiss stays, I'll be happy for us. It's not my problem."
Chelsea had an offer of 80m for the Ecuador midfielder rejected last week, though are expected to try again.
Brighton have now upped their price to 105m to sell Caicedo this month.