The midfielder missed the 1-0 defeat at Motherwell with the ankle injury that has troubled him in recent weeks.
And manager Csaba Laszlo does not know whether the swelling will go down before Hibs visit Tynecastle on Saturday lunchtime.
"I can't answer," Laszlo told Hearts News. "He has this inflammation in the ankle and I hope this week he will be okay."
Stewart scored the winning goal against Celtic as Hearts made the Co-operative Insurance Cup semi-finals last Wednesday, days after being jeered during a goalless draw against Falkirk by fans unaware he was playing through the pain barrier.
"He had a very quick run of games behind each other and this is why we took him out on Saturday," Laszlo added.
"It was great for him to shoot the winning goal against Celtic but he was not 100% fit on Saturday so it was better for Mike to have people who are 100% fit."
Source: Team_Talk
