The Scotland back-row has been sidelined for the last three weeks after coming off with a head injury in the 36-10 loss at Wakefield Trinity - his first game for Huddersfield in more than ten months.
Ferguson, 31, has complained of concussion symptoms and suffered blurred vision and, ahead of Friday’s relegation battle with Hull KR, Woolford conceded he is no nearer an answer.
“We’re still unsure about what’s wrong with Fergie,” he said, having also revealed prop Paul Clough will be out for up to six weeks after breaking a hand in Friday’s loss against Catalans Dragons.
“He’s still got symptoms and he’ll be seeing a neurologist to see what’s happened.
“I wouldn’t be anticipating him back any time soon and we’d be lucky to see him again this year.
“He’s been through a pretty traumatic couple of weeks.
“They’ve had to rule a lot of things out but he’s still not quite right so hopefully we can get some answers there in the next week or two.”
Ex-Bradford Bulls forward Ferguson had to wait until the end of May to make his season debut on loan with Featherstone Rovers having struggled to overcome a previous back injury.
Asked about his mental state, Woolford said: “He’s holding up alright.
“Early doors after the incident he was a little bit concerned.
“There was concerns there could be something serious but that’s all been ruled out.
“He’s seen a concussion expert and an eye expert and they’re not too sure what the problem is.
“There’s not too many neurologists in the country but we’re in the process of getting him booked in and fingers crossed he’ll make a full recovery.”
Former Bradford and St Helens prop Clough, 31, could miss the bulk of Huddersfield’s battle to pull clear of the relegation zone.
"Cloughy will be missing for four to six weeks so that's not great news but we've got guys like Matty English and Adam Walne coming back into contention for this week," coach Woolford, who also hopes to have captain Leroy Cudjoe in the mix.
“Leroy trained today so we’ll make a decision on him tomorrow. He trained 13 v 13 full contact.
“We’ll talk to him later on and he’ll decide whether he’s right.”