Midfielder Kieran Lee has undergone knee surgery, Wednesday manager Jos Luhukay has today confirmed.
It is understood Lee went under the knife in London three weeks ago.
The 30-year-old, whose contract runs out at the end of the season, has not made a senior appearance in almost 12 months due to multiple injury problems.
Luhukay, who has no fresh injuries to contend with heading into tomorrow's Championship showdown with Blackburn Rovers, told The Star: "I'm not the doctor but we take a lot of time with Kieran.
"He had his surgery three weeks ago. We give him time and we can't do anything more. He is here every day for his treatments."
Lee, signed by Wednesday in May 2012, has played over 170 matches for the Owls.
Asked on a timescale on when Lee will resume first-team training, Luhukay said: "We hope maybe in January (he will be back out on the pitch) but I can't say 100 per cent.
"When in the next days and weeks the progression is there, maybe Kieran can start (training) in January. Hopefully.
"It is not a guarantee. We must wait for him to come back on to the field and see how he reacts and his intensity. That will give us a view on maybe how long he takes."