McGrath dropped out of Australia's tours to South Africa and Bangladesh earlier this year to help his wife Jane fight a relapse of breast cancer.
With her health improving, McGrath, a veteran of 119 Tests, is working on his fitness and keen to represent Australia again.
But Hilditch said it was unclear whether the Australian spearhead would play at the ICC Champions Trophy in India, which ends just weeks before the much anticipated Ashes commence on November 23.
"We're going to sit down with the coaching staff and map out Glenn's fitness and how he needs to best get back into playing cricket again," Hilditch told Australian Associated Press late Monday.
"That (the Indian series) will be something we'll talk through with Glenn and the Australian coaches and make sure Glenn's program is exactly as he wants it and we need it to be so he's ready to play in the Ashes.
"We haven't really started that process yet. We will do that probably in the near future."
McGrath was injured for much of the last Ashes series in England and was sorely missed by the Australians, who lost the trophy for the first time in 18 years.
Hilditch predicted the upcoming series in Australia would be tight, despite England's ordinary recent form.
"The reality I think is they'll come ready to retain the Ashes and I think they'll be a very strong side," Hilditch said.
"We'll have to play at our very, very best to beat England.
"Whatever they've been doing in the last few months and in the next few months, I think come Ashes time it is going to be all fairly irrelevant."