Kisnorbo, 30, hasn't played since March 22 last year after sustaining the injury in a League One game with Leeds United last season.

The Australian has been on a long road to recovery since, spending time in the United States working on his re-hab before recently returning to Leeds training.

Kisnorbo, who hasn't played for the Socceroos since November 2009, is now edging closer to re-joining the Whites squad in full training and Grayson praised him for his attitude.

"Paddy has worked really, really hard, and he has got to the stage now where he has been able to join in the warm-up and do some ball-work," Grayson told

"It's been a long, hard road for him and where he is now is really encouraging.

“There's still no timescale, but we're really pleased with how he is coming along."

Kisnorbo, who won Leeds' 2009/2010 Player of the Year award, comes out of contract at Elland Road at the end of this season.

The Australian's long-term injury has put doubts on his future at Leeds, but Grayson's comments are positive for Kisnorbo's hopes of winning a new deal to stay with a club battling for promotion to England's Premier League.