Kisnorbo, 29, missed Australia's 2010 World Cup campaign after rupturing his Achilles tendon whilst playing with the Whites in March.

The luckless defender could now also miss the 2011 Asian Cup in Qatar which runs from January 7-29, with Leeds confirming they won't put a timeframe on his return.

"From the start, the assumption with Paddy was that his injury would take months to heal rather than weeks," Leeds boss Simon Grayson told the Yorkshire Evening Post.

"I'm sure he's desperate to get back just as we'd want to have him fit and available but we won't force his recovery and I still don't want to put a timescale on his comeback.

"He'll take as long as he needs to."

Leeds United, who will begin pre-season on Thursday without Kisnorbo, hope to see the Australian ready for action in November but won't rush him back.

It is understood, Kisnorbo tentatively hopes to return to light training next month but the Whites insist they will be happy to see him back in the closing weeks of 2010.

Such a return may mean he's short of game-time when the new Socceroos coach names his squad for Qatar.

Grayson added: "There's no possibility of him being fit for the start of the season so there's absolutely no reason to rush him.

"I'd much rather he took his time and came back in perfect shape. It'll be a big boost when he does."

Kisnorbo will also miss much of Leeds' return to England's second tier as they hope to consolidate their position in the Championship.