Parkinson admitted ahead of Sunday's tie with Halifax that Hanson has been struggling with a thigh injury in recent weeks, leading to City's top-scorer missing the trip to the Shay Stadium.
Following the Bantams' 2-1 victory over the Shaymen, the City chief revealed that Hanson has received an injection in a bid to finally solve the issue.
If it doesn't work, however, the Bantams plan to send the striker to the National Football Centre at St George's Park in Burton for further medical treatment.
Parkinson said: "We have given James a steroid injection. If he is not back in full training by Tuesday and flying about and ready for the weekend, then we'll send him away to St George's Park for a week.
"We've tried everything we can to get him right and he might just need a week away for intensive treatment to get him sorted.
"We need James back but we need him back the way he was playing at the start of the season, not the way he has been playing in the last few weeks.
"Matt Barrass (City's Head Physio) and his medical team have tried everything they can to get him right. He's had this steroid injection on Friday and he needed two full days afterwards to rest before he can do anything again.
"Hopefully he's back training by Tuesday but, if not, we'll send him away for a week. If that happens, we hope that he'll be fine the week after Preston (City's next game, Saturday 15 November 2014)."