The centre-back has spent over 10 hours in an oxygen chamber in a bid to ease the problem while the Leeds physio team have supplied round the clock treatment.
If Butler is passed fit, he is expected to return to the heart of the defence, alongside Sean Gregan, with Matthew Kilgallon likely to make the move to left-back to replace the suspended Stephen Crainey.
If Butler misses out Frazer Richardson may take the left-back role, despite favouring the other side of defence, while Dan Harding could also come into the equation.
The Leeds boss is expected to stick with the same midfield that started against Preston, but must consider the right side of attack.
Richardson grasped the opportunity against Preston when he turned in a superb display and is a contender to be handed the role again tomorrow. David Healy and Robbie Blake are Blackwell's other options if he opts for a natural forward.
Leeds (from): Sullivan, Kelly, Butler, Gregan, Kilgallon, Harding, Douglas, Derry, Miller, Richardson, Healy, Blake, Hulse, Lewis, Bennett, Stone, Beckford, Moore, Bakke.