The South African tweaked ligaments in his right knee after Derby striker Dean Sturridge fell on top of him during Saturday's 2-2 draw at Pride Park.

Radebe was stretchered off in the 50th minute and left the ground on crutches.

He could now be on the sidelines for at least two weeks.

O'Leary: "I don't think they'll come here and sit on a one-goal lead"

It is the second blow for Leeds manager David O'Leary, who will also be without goalkeeper Nigel Martyn for the Elland Road clash.

The England international will miss his fourth straight game due to a rib injury.

An unhappy O'Leary said: "Losing Lucas is a big, big blow for us. He is a fantastic defender and we always look a better team when he is there."

O'Leary can at least call upon Austrian international Martin Hiden to fill the void in the centre of defence following his recovery from a stomach bug.

David Wetherall is O'Leary's other option, but having been at fault for the Rams' equaliser and for Tony Cottee's winner in the 1-0 home defeat against Leicester last month, he is likely to be dropped.

With 19-year-old Paul Robinson due to continue in goal, O'Leary's only other decision is whether to recall Danny Granville to the left wing-back position.

Granville is eligible to play in European competition despite being in the middle of a two-match domestic ban.

But he could be on the bench after Ian Harte proved his form following his recall to the side for the game at Derby.