The England international is in training again after recovering from a foot injury sustained against Fulham in September.
In his absence, Wigan have struggled and manager Chris Hutchings has lost his job.
"I've got to take it one step at a time," Heskey told the club's website.
"I've been told I'm going to feel a few twinges now and again, and that it's going to take a while for everything to get back to normal again.
"For a start, I'm six weeks behind on fitness, and although I've been in every day and keeping up my strength in the gym and in the pool, nothing's the same as being out there on the field with the players.
"There have been quite a few changes too while I've been sidelined, with the manager [leaving] and the way results have gone, so it's been doubly frustrating that I haven't been able to play a part.
"Now we'll see what happens next. I'm hoping to be available for the next game, but we will have to see how things progress over the next week or so."