The former Wigan and Newcastle stopper was out for month with the injuries he picked up in the draw against Everton.
He returned to training last week and was scheduled to be drafted into the squad for the game against Swansea.
However, he asked for more time to regain fitness and was given another week, but has subsequently aggravated the injury.
"Titus trained with us last week for two days and because he had had no reaction I put him into the squad for the game on Saturday," Martin O'Neill explained to The Chronicle.
"However, he came to me on the Friday and said he did not think he would be ready.
"I said that was fine and he could do more training over the weekend.
"However, having done some training, his Achilles is sore again and that is why he missed out again on Tuesday night."
