Wesley Fofana was originally ruled out for up to five weeks by Maresca when he sustained a hamstring injury against Aston Villa.
The centre-back seemed to pick up the problem after slipping midway through the second half of the 3-0 victory at the start of December.
Since that initial estimate was given by Maresca, though, the Italian has rowed back on those comments.
Speaking last week, the Blues boss stated that Fofana could now be out for a “long period”, suggesting the injury was much worse than originally thought.