Barton sustained a foot injury against Reading on August 15 and has missed the last three games.
Butt was forced off at half-time against Huddersfield with a foot problem but was expected to train over the weekend and come into contention to face the Foxes.
However, Newcastle face a striker shortage with Andy Carroll and Xisco ruled out with groin injuries and leading scorer Shola Ameobi doubtful with a foot problem.