Having already spent four weeks sidelined with a torn quadriceps tendon, Hird says it will be at least that long again until the midfielder is ready to return.
"I'd say he's at least four or five weeks away from coming back, it's not a good injury he had and we want to be very cautious," Hird told reporters on Friday.
The initial forecast was that the injury would sideline Zaharakis for at least a month.
Hird said Zaharakis had not sustained a fresh tear, but had experienced soreness and the Bombers were being very cautious to ensure he could play at the business end of the season.
"If you ask anyone who's had one, you have to be very careful with them and he's a fantastic player for us, our reigning best and fairest, a young player," Hird said.
"We're going to be really, really careful with his quad so we've got him for our last four or five games, or two or three games of the year."
In brighter news, Hird said Jason Winderlich would play in the VFL this weekend after a long injury absence.
Winderlich has not played since injuring an anterior cruciate ligament in round four last season.
His comeback was delayed by hamstring problems this season.
Hird said Winderlich was likely to need two or three games in the second-tier competition before he would be ready for an AFL return.
