Millwall midfielder Tamika Mkandawire is expected to be out for four months after undergoing an operation on a knee injury.
The Championship club were initially hoping that the 28-year-old would only require a month on the sidelines, but surgery revealed the injury was worse than first believed.
Mkandawire has damaged cartilage in his knee and the Lions are likely to be without the former Leyton Orient man until well into the New Year.
Physio Bobby Bacic told the club's official website: "Scans had been inconclusive, so the surgeon made the decision to look inside the knee to get to the root of the problem.
"A section of Tam's cartilage had been damaged and the surgeon duly operated on this area. Tam will be looking to return in four months' time."
Mkandawire, who moved to The Den in 2010 from Leyton Orient, has made 15 appearances in all competitions this season.