Humanitarian notions that five‑setters are reducing the best players to physical wrecks is somewhat diluted by the presence in Sunday’s US Open final of Novak Djokovic and Juan Martín del Potro, who have experienced more than their share of physical and spiritual hurt in long, garlanded careers.

There is the counter argument of Rafael Nadal’s retirement when his right knee collapsed after he had lost two sets against Del Potro on Friday. But the Spaniard – who played the two longest matches of the tournament going into his semi-final – is not advocating three-set slam matches, even in the early rounds, a proposition gathering some fringe support.

Standing above the clamour is the Tower of Tandil himself, Del Potro, who beat Nadal and Roger Federer to win his only grand slam here nine years ago. Pain in his wrists prevented him from defending his title in 2010, then worsened to the point where he spent more time in the company of surgeons than his rivals on the Tour.

Del Potro did survive, dramatically so. At 29 and back to near his best, the Argentinian attracts admiration throughout the game for the way he has fought back from nearly quitting the sport in 2015 to a career-best No 3 world ranking, and now is on his favourite stage again.

In front of him on Sunday is a man who has beaten him 14 times in 18 contests and in all four of their slam matches.

Djokovic missed last year’s tournament because of a chronic elbow injury that required minor surgery in January. However, his worries here have been induced by the extreme heat, rather than the strain on his limbs and he appreciated the significant drop in temperature for his routine straight‑sets win over Kei Nishikori in the second semi-final.

The finalists appear to be in good health, although they will be as tired as any player would be after six matches in a fortnight. And they will do their best to ignore fatigue, however long the match lasts.

“He’s a dear friend, someone I respect a lot,” the Serb said of Del Potro. “We all felt for his struggles with injuries that kept him away from the tour for two, three years. But he was always a top-five player in the eyes of everyone, even when he dropped his ranking.”

Djokovic, a two-time champion in New York, will start as the favourite, despite trailing Del Potro by three places in the ATP rankings, which only confirms that all is not as it appears in tennis.