The England U-21 international injured his knee in Tuesday night's FA Cup replay with Wigan in a clash with striker Jason Roberts.
The Whites may also have to do without Eddie Lewis and Liam Miller after they were subbed on Tuesday with injuries.
"They have responded quite well but it is too close to call at the moment and we shall make a decision on them nearer the time," Kevin Blackwell said on the official Leeds website.
Rob Hulse is suspended after picking up five yellow cards for the season, the last of which came against Brighton last weekend for dissent.
New recruit Joel Griffiths has not received international clearance in time to play and now hopes to feature in Monday evening's reserve game at Bolton.