Novak Djokovic insisted that his hamstring issues are a genuine concern after more injury dramas in his Australian Open second round.

The nine-times champion left the court for treatment in the second set of what was ultimately a comfortable victory, 6-1 6-7 6-2 6-0 against French qualifier Enzo Couacaud.

The true state of his body remains, not for the first time, something of a mystery, but it will get a sterner test in the next round when he meets Grigor Dimitrov.

‘I am worried. I mean, I cannot say that I'm not. I have reason to be worried,’ he emphasised, despite moving better as the match wore on. Two years ago I had kind of similar circumstances here in Australia with a different muscle (abdomen) where I had a tear and I had to deal with that. Somehow I pushed it through and won the tournament.’

Rafael Nadal is unlikely to play again until the European clay court season after being ruled out of tennis for around eight weeks.

The defending Australian Open champion underwent an MRI scan in Melbourne which showed a grade two injury to a muscle in his left hip flexor.

The cure is anti-inflammatory treatment and rest, meaning that he looks almost certain to miss the big hard court tournaments in the US in March. A possible return would be the Monte Carlo Open, which would allow him to launch towards his most realistic goal of the year, claiming yet another French Open.

Nadal was joined on the scrapheap by number two seed Casper Ruud, making it the first time in 21 years that the top two seeds in the tournament have gone out before the third round.

The Norwegian was beaten 6-3 7-5 6-7 6-2 by American Jenson Brooksby and is yet another character featuring in the new Netflix Break point series who has met an early end in Melbourne.

However it might have more to do with the fact that he played too many lucrative exhibition matches around the world in the off-season, including with Nadal around South America, rather than resting up and honing his game.

The same could be speculated about world number nine Taylor Fritz, who also features heavily in Break Point. The world number nine also played in the off-season, in Saudi Arabia, and he was defeated 6-7 7-6 6-4 6-7 6-2 in four hours by Australian wildcard Alexei Popyrin.

Yet another Netflix character, women’s number two seed Ons Jabeur, also fell when she was knocked out in three sets by Czech Marketa Vondrousova.

Speaking immediately after his match to Eurosport, Djokovic gave a similarly bleak assessment of his fitness. 

'To be honest, it's not good at all,' he said. 'I'll take it day to day. It was better last match than tonight.

That's all I can say, now it is up to God to help me, and physio and everyone, let's take it day by day. 

'I don't know, I hope I'll be able to recover and be ready for a tough match up next match.'