Leeds are refusing to set a date for Patrick Kisnorbo’s return to their defence.
Kisnorbo, 29, has been badly missed since injuring his Achilles just six minutes into the home defeat against Millwall in March.
The Australian, who joined United from Leicester in the summer of 2009, had another operation a few weeks ago.
Leeds boss Simon Grayson said: “We will be guided by the surgeon and the physios. Paddy will be back when he’s back.
“It may be February or March but if it takes a longer or shorter time we will run with that. Paddy will be like a new signing for us eventually.”
With reserve fixtures in short supply, United have arranged another friendly behind closed doors next week – this time against Sunderland – so some of the players who have been out injured can improve their match fitness.
Striker Billy Paynter has an outside chance of returning to the first-team squad for Monday night’s home game against Cardiff but defender Ben Parker is still some way off a senior comeback.