The 31-year-old tweaked his hamstring in round four against the Sydney Swans, and coach Chris Scott admits Chapman won't be back playing for 'quite a while'.
"Unfortunately he did have a little bit of a setback with his hamstring last week, so we're going to be extremely conservative with him," Scott said on Tuesday.
"He'll take at least another few weeks to rehab that, and then there'll be a period where he needs to get some match fitness back, either through the VFL or through our training.
"It's really hard to determine a return date for him; suffice to say it's going to be quite a while."
It has been a frustrating year for Chapman, who will have missed eight weeks of football after the club's bye round next weekend.
"It's devastating for players towards the end of their career to be cruelled by injury, but this is something that should be treated in isolation," Scott said.
"He was in fantastic form before he hurt his hamstring. Once he gets the hamstring right, we're really confident that he can come back and add to our 22.
"It's easy to think really long term, what does the future hold for ‘Chappy’? We've got to make sure that collectively we view the end of the season as the only thing that matters for ‘Chappy’.
"If we can get him in some good form towards the end of the season, he's going to be a really valuable asset."
Steven Motlop will miss this weekend's match against Greater Western Sydney, having pulled up sore after the club's win over the Gold Coast on Saturday night.
"He's got a little bit of a knee issue, some patella tendonitis that we need to manage," Scott said.
"He'll take the chance to have two weeks off with the bye next week as well, and hopefully get him back feeling a bit better post-bye."
James Podsiadly is likely to return from a knee problem, while Billie Smedts, Jesse Stringer and Jordan Murdoch are in the mix for the meeting with the winless Giants.
Hamish McIntosh is in line to play in the VFL after the bye weekend, as is Jared Rivers, who has made 'good progress' in his eight-week rehabilitation from a knee injury.
