Pat Cash: Novak Djokovic is one wrong step away from hamstring injury ruining his Australian Open

Australian tennis legend Pat Cash and a top doctor agree that Novak Djokovic's hamstring injury is very serious - and 'one wrong step' could ruin the tournament for the Serb superstar.

The nine-time champion told media on Monday night that he was being singled out for criticism around the leg issues he has been suffering, and angrily denied that he's been exaggerating the extent of the injury.

Djokovic's hamstring has been bandaged throughout the tournament, though there was no sign of any ill effects in his recent performance againstAustralia's Alex de Minaur.

Cash and sports medicine professional Dr Peter Larkins believe the hamstring is certainly on the mend, but it wouldn't take much to derailDjokovic.

'Just one strange move and if you are wrong-footed, or lunging, and it hasn't quite healed 100 per cent, there is a risk,' said Cash.

'There is no doubt there is a risk he could do something in the next few matches. It could be a strange move and he could pull up and it would be the end of his tournament, unless it is in the final and he would fight through.'