Only something 'miraculous' can stop Djokovic in Melbourne: Rod Laver

Melbourne: Novak Djokovic has already been pushed to four sets in two of his early matches at Melbourne Park but Australian great Rod Laver says engravers should get to work putting the world number one's name on the Grand Slam trophy for an 11th time.

Djokovic is eyeing a record-extending Melbourne Park title that will also take him past Margaret Court's haul of 24 majors but the Serb has not had it all his own way and was pushed hard by teenager Dino Prizmic and local hope Alexei Popyrin.

Laver, the only player to win the calendar Grand Slam twice, is still convinced Djokovic will glide past challengers after the 36-year-old downed Tomas Martin Etcheverry to set up a fourth round meeting with Adrian Mannarino.

"It's almost like he's priming himself to get through to the final," 11-times Grand Slam winner Laver said on Saturday after arriving in Melbourne from California.

"He'll lose a set somewhere in these five-setters and I'm thinking, 'Is he having us on?' because he could win this in two and two and two (6-2 6-2 6-2)."

Djokovic claimed last year's title despite playing with a small tear in his hamstring and 85-year-old Laver, who has the centre court at the Australian Open named in his honour, said it would take something extraordinary to dethrone him.

"He's such a great athlete to begin with, but his mind also is tennis and so he sees it almost unfold in front of him, just what he should be doing," said Laver.

"That's how he's being a great champion.

"He serves well, his groundstrokes are unbeatable, so I have to believe, unless someone miraculously plays their best tennis to knock him off they can start putting part of his initials on the trophy now."