The 30-year-old Australian has been sidelined since undergoing surgery to repair his Achilles tendon, which he ruptured in a League One game with Millwall in March last year.
Grayson said: "Paddy has worked really, really hard and has got to the stage now where he's been able to join in the warm-up and do some ball-work.
"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's coming along."
Kisnorbo, who opted to step down a division when joining Leeds in the summer of 2009 following his release by Leicester, won the fans' and players' player of the year awards in his first season at Elland Road.
Source: PA
