Tuesday's hat-trick hero against Bolton took a whack on his troublesome ankle in the 6-0 quarter-final victory and has been treated around the clock in a bid to be fit.
Goran Bunjevcevic looks unlikely to recover from a thigh strain although boss Glenn Hoddle would not shut the door on his involvement.
Dean Richards is available again after being cup-tied against Bolton but Christian Ziege serves a one-match suspension after notching up five yellow cards.
Glenn reported: "Les is struggling a little. He got a kick in the first half and the ankle swelled up again. He will be treated right up to Saturday morning. Apart from that everyone is okay from Tuesday night.
"Goran has a few fibres in his thigh, it's getting better, improving and he might have an outside chance. He'll be there or there abouts."
Fulham will be without Steve Marlet for another month as he recovers from a compressed knee fracture.
Les Ferdinand is our major concern before Saturday's Premiership encounter against Fulham at the Lane.