Striker will miss five games for Bradford City.
Bradford City have confirmed that James Hanson has been ruled out for up to four weeks with a thigh strain.
The striker picked up the injury during the warm-up before Tuesday's match at Milton Keynes Dons.
Parkinson had already ruled Hanson out of this Saturday's trip to Colchester United but he now knows he will potentially be without the striker for the next five games after that following the results a scan on the injury.
Along with the suspended Alan Sheehan, Hanson now joins the injured trio of Andrew Davies, Lewis Clarkson and Matthew Dolan currently on the side-lines.
As a result of the injuries and Sheehan's suspension, apprentice defender James Pollard has joined fellow scholars Reece Webb-Foster, Sam Wright and James King - all of whom travelled to MK Dons - in City's squad for the Colchester match.
Exclusive full match commentary of the game is on Pulse 1 Sport with Tim Thornton and Wayne Jacobs.