IT is more than six years since the assembled tennis press were first invited to write the obituary for the career of Rafael Nadal, the King of Clay, the southpaw slayer of champions, the ultimate fiddler of sportswear.

The Spaniard, then only 23, had lost all three matches in the world tour finals at the 02, failing to win a set. His knees may not quite have been squeaking but it was obvious they were sending an insistent message to Nadal’s brain.

They were crying for a halt. The Spaniard had pulled out of Wimbledon after losing in the French Open to Robin Soderling and his discomfort was obvious throughout the season.

Most correspondents shied away from donning the black cap and sentencing the Spaniard to exile from the tennis court but many murmured that the boy from Manacor had run too many hard miles, pounded and twisted too many times on unforgiving courts.

Nadal addressed this line of inquiry with both his customary politeness and his unwavering resolution. He said he would be back. Within a month, he was part of the Spanish team that won the Davis Cup. Within a calendar year, he won three grand slams: the French, Wimbledon and the US Open. He had climbed the mountain, on restored knees, yet again. But, at 29, the professional obituaries for Nadal now have a chilling substance. His two losses in 2016 indicate the glory days have gone.

The brutality of top-class sport suggest they will never return. Novak Djokovic’s demolition of the Spaniard in Doha was complete. Nadal lives to compete and the ease of the world No 1’s victory will provoke much contemplation in the Mallorcan’s camp.

If Nadal believes he cannot beat the best, accepts that grand slam titles are in the past, he will walk away. The second defeat of 2016 brings this eventuality at least a step closer. Again, there is no shame in losing a five-set match against a free-swinging Fernando Verdasco.

But the manner of Nadal’s defeat was numbing for those who have watched him wrench victory from the most unyielding of circumstances. The records show he has won 67 titles, including 14 grand slams.

The eyes testify that he did so through a mixture of technical ability, astonishing energy and a will that could have survived a direct hit from a missile.

This indefatigable warrior lost in unRafa circumstances in Melbourne. At 2-1 up in sets, he lost the fourth to Verdasco in a tie-break, confounding those who witnessed Nadal consistently make the big plays at precisely the right time in his 15-year career as a professional.

The events of the fifth set were far more worrying. Verdasco, who hit 90 winners in the match, was aggressive, accurate and relentless on his forehand. But Nadal had broken and was 2-0 ahead. He then lost six consec-utive games. The once irresistible tempest had been reduced to a whisper on the Rod Laver Arena.

So can he blow again? He was typically positive in defeat. “I have been playing and practising great and working so much. Let’s keep going,” he added.

However, the prognosis for success in grand slams casts a dark cloud on such forgivable sunniness. The world No 5 has not won a major since the French Open in 2014. Wimbledon seems beyond him. In recent years he has lost there to Lukas Rosol (2012), Steve Darcis (2013), Nick Kyrgios (2014) and Dustin Brown last year.

He has not won the Australian Open in six years and his 2013 success at the US Open was followed by him missing Flushing Meadows with an injury and then losing to Fabio Fognini in the third round after taking the first two sets.

The French Open, a title Nadal has won nine times, has thus become crucial to the former world No 1’s future. If he can win in Paris in the summer, then his faith will be restored, his body energised for a summer that includes an Olympics where he seeks to gain a second gold medal in the singles.

But if he loses, particularly, almost unthinkably in an early round? Nadal has never disguised his distaste for making up the numbers and admitted he could not see himself playing on when the major prizes are beyond him.

Roland Garros in the late days of May and those of early June could herald a resurgence or confirm a decline. The latter is the more likely.

There is no pleasure in saying this. As he hobbled from the 02 in 2009, wincing at his aching knees and bruised by three cuffings in a week, he paused to address the press. “I wish you all a Happy Christmas with your families and I will see you next year,” he said. He was true to his word.

But in 2016 there are ominous signs that, while the wonderful personality endures, the substance of a champion has cruelly deserted a warrior who must fear the dying of the light.