Striker Heffernan has yet to start a league game for the Owls since moving from Doncaster Rovers and was substituted during the midweek Carling Cup defeat at Scunthorpe United.
Speaking ahead of today's trip, Irvine said: "Paul is a squad player and someone I hope will make a very good contribution as the season goes on.
"It's not happened yet but he has proved that he can score goals in this division and above. We know Paul has qualities and he knows the job that is required. The two thing have to come together."
The Owls have rejected a 400,000 bid from Blackpool for striker Marcus Tudgay.
Owls fan Mick Wadsworth is in caretaker-charge of Hartlepool following the resignation of former Owls manager Chris Turner and has ex-Owl Ritchie Humphreys on his staff.