Floyd Ayite is out of this weekend's game with Millwall.
The midfielder limped off with a hamstring injury after 68 minutes of the sensational game at Bramall Lane on Tuesday night.
And Fulham manager Slavisa Jokanovic has revealed that the Togolese could be missing for "a few weeks".
Talking during his press conference ahead of the game with the Lions this weekend, Jokanovic said: "Ayite and Lucas Piazon definitely out of the squad.
"Floyd Ayite will be outside of the squad for a few weeks."
Meanwhile Jokanovic and his medical staff will be assessing the situation with a number of his other players too.
He added: "There are a few players that we have some question marks over, we must observe and look at them."
When pressed on who, he replied: "All of them."