This piece is being written amidst first round action, but a lot has already happened to have a decisive impact on the year’s final major even before the first point had been played at the US Open. World No 2 Andy Murray, the 2012 champion, who was unseated from the summit by Rafael Nadal only a couple of weeks ago, joined the likes of Novak Djokovic, Stanislas Wawrinka, Milos Raonic and Kei Nishikori in an elite group of players absent from Flushing Meadows.

For Murray and Djokovic, the two men that dominated men’s tennis in 2016 and have been the two most successful over the past five years, 2017 was as pear-shaped as it could get. That it came off the back of a historic year for both – Murray finishing the year as World No 1 and Djokovic completing the career Grand Slam in Paris – has made it an even bigger shock.

Even so, what has arguably made their absence all the more conspicuous is the return to the top of men’s tennis for Nadal and Roger Federer – who have shared three majors and four ATP Masters 1000 titles between them this year, and barring a major upset should be the top two of men’s tennis post-US Open, regardless of the final outcome.

Federer and Nadal, the two most decorated men’s tennis players, have not only defined tennis’ most illustrious era but also created the sport’s most high-profile rivalry. It was under the shadows of these two giants that Djokovic managed to carve out an all-time great career for himself, while Murray squeezed in a legacy – and knighthood – for himself as well.

But with Federer and Nadal doing the unthinkable after returning from prolonged injuries – the latter having defined a career out of it – the spotlight immediately falls on Murray and Djokovic and whether they can rebound similarly, even if not as emphatically.

Unfortunately, the first attempt to answer that question can only come at the Australian Open next year, where the Fedal comeback formally began in January.

Hopefully both Federer and Nadal would be in the draw by the time you read this. But unlike the Australian Open – and even Wimbledon – where they were drawn in opposite halves, Fedal are on a collision course for a blockbuster semifinal at Flushing Meadows, where they’ve anomalously never met.

Murray’s last minute withdrawal meant that Alexander Zverev – Montreal and Rome champion – is the highest seed in the bottom half, with Marin Cilic – US Open 2014 champion and this year’s Wimbledon finalist – the other highest-profile name in there.

This means that even outside contenders like Nick Kyrgios, Gregor Dimitrov (Cincinnati champion), Juan Martin Del Potro (2009 US Open champion) and Dominic Thiem are in the top half. Kyrgios, who reached the Cincinnati final after taking out Nadal in the quarters, could meet Federer in the Round of 16; while Dimitrov, who played an epic Australian Open semifinal against Rafa this year, could meet him in the quarters.

Now, there are basically two broad possibilities as to what might transpire in New York, and each would have a contrasting impact on what has been an oddball of a year – despite being so familiar.

The first being the obvious one that one of Federer or Nadal would win the US Open. This would establish the winner’s return to dominance of the sport, and would ensure they finish the year as the number one and be the favourite heading into next year as well. If Federer wins, he would push him further ahead of the chasing pack led by Nadal as the greatest of all time, while if Nadal wins this year’s four majors would be evenly split between the two, making it truly the year of the Fedal.

The other possibility is that neither of the two win and we see a completely different winner. If this winner comes from outside of Cilic and Del Potro, they would be first time major winners and could in turn push their name into the mix as the player to lead men’s tennis in both the distant and near future. This group is led by Zverev, Kyrgios, Thiem and Dimitrov – in ascending order of age – and a first major win at the US Open could just be the push their career needs.

More so than the first three, it’s Dimitrov at 26 years who urgently needs a headline win to separate himself from the also-rans and put his name as someone who will challenge for majors in the coming years.

It would be a massive sporting shock if Zverev doesn’t end his career as a multiple major winner. And so, for him it’s a question of when. But as things stand, he is yet to make a Grand Slam quarterfinal in his career.

Kyrgios hasn’t made a major quarter since Australian Open 2015, and with him it’s the question marks over temperament and never the skill that is always the biggest hindrance. The way he blew Nadal off the court in Cincinnati was just the latest example of what he can do. It remains to be seen if he can put two weeks of that level together to have a shot at a major. If that maiden win doesn’t come for the Aussie soon, one fears that he won’t hang around too long to see the fulfillment of his talent.

Meanwhile, Thiem has failed to impress outside of clay and needs to address his game and court positioning to be a threat on faster hard courts.

No matter what happens, there is bound to be some level of romanticism for tennis aficionados.

A 20th major for Federer to cap off one of the greatest comebacks of all time with a three-major year?

A 16th major for Nadal to make it truly a Fedal year and push the Spaniard to the year-end World No 1 ranking?

The long touted ‘Baby Federer’ Dimitrov finally breaking the shackles and emulating the idol that he’s modelled his game after?

Kyrgios or Thiem to overcome their respective limitations and formally announce their arrival to the world in New York?

Zverev kicking off his potentially voluminous Grand Slam winning tally at 20 years of age?

Or a complete underdog coming out of nowhere to win it all?

Take your pick.