Nottingham Forest could be without key midfielder Andy Reid until March after he suffered a fresh setback in his return from a groin injury.
The 32-year-old, who hasn't played since the East Midlands clash against Derby County in September, was hoping to return this month, but now requires an operation on the problem.
"We have seen four specialists and decided to go down this route and hope he gets back well before the end of the season," Forest boss Stuart Pearce told BBC Radio Nottingham.
"We have done the recovery on his injury which took him up to a certain level but couldn't break past a certain level of pain he was getting."
Reid had the best goalscoring season of his career last term by netting 10 goals in all competitions. He has made just six appearances in 2014-15.
