Tiatto, who has been sidelined since the Boxing Day victory over Aston Villa, returned to training with the City squad on Monday but had to pull-out of Tuesdays session because of pains in his back.
"We are having a real job, not getting him fit, but getting him fit to play," manager Kevin Keegan told www.mcfc.co.uk
"He is coming in and getting niggly injuries. On Tuesday it was his back which was sore, another little problem for him. And he certainly will not be considered for the game on Saturday.
"Somewhere down the line the physio will have to look and see where the relationship is between all the little injuries."
"He came in and trained very well on Monday. The one thing you can say about Danny is that he can miss a month's training, as he has a few times while I have been here, but he comes in and it is as if he has never been away."
"He has had a reaction so we will have to wait and see, but Saturday is too soon for him."