Who will be world number one after the US Open?

The US Open will provide a sub-narrative to see who among the ATP contenders will emerge as world number one as well as the bigger story of who will win the final Grand Slam of the season in the probable absence of Novak Djokovic and with Rafael Nadal looking to extend his all-time record at the top of the slam list to 23, which would draw him level with Serena Williams and take the Spaniard past Steffi Graf.

Up to five players can be installed as number one when the dust settles in Flushing Meadows. There could have been six contenders but Alex Zverev will not compete at the US Open due to a lack of competitive play following his injury at Roland Garros.

Nadal will regain number one spot with US Open win

Nadal, a priori, has the easiest route to the number one ranking. The Spaniard will go into the tournament on 5,630 points and he has none to defend as he did not compete in New York last year. If Nadal is triumphant for a record-equalling fifth time at the US Open, he will be crowned number one. If he does not lift the trophy, his ranking after the tournament will depend on other results.

The second contender is the current number one and defending champion Daniil Medvedev. The Russian would be left on 4,885 points if the 2,000 points he earned last year are deducted. Like Nadal, the only surefire way for Medvedev to remain number one is to win the tournament, as any other result would leave him dependent on other results. Were Medvedev to beat Nadal in the final for example, the Russian would have 6,885 points compared to 6,830 for the Spaniard.

Stefanos Tsitsipas is also in the mix. The Greek is, along with Nadal, one of the players with the fewest points to defend as he was beaten in the third round by Carlos Alcaraz last year. However, it would not be sufficient for Tsitsipas to become number one if he won the US Open: if Nadal was on the other side of the net in the final, the Spaniard would again come out as number one in the world.

Alcaraz could become youngest number one in ATP history

Alcaraz, who rose to global fame during his US Open run last year, will start the US Open with 4,740 points after deducting the 360 he earned last year. If he were to win the tournament - and depending on how deep into the two weeks rivals such as Nadal, Medvedev and Tsitsipas go - 19-year-old Alcaraz could become the youngest number one in history at just 19 years old, beating Lleyton Hewitt’s record.

The last contender is French Open finalist Casper Ruud, who only has 45 points to defend from last year, meaning the Norwegian could claim the number one spot if he wins the title in New York with 6,650 points.

Why can’t Djokovic regain number one at the US Open?

The Serbian, who is still waiting to find out if he will be able to play in New York, would go into the US Open with 3,570 points if the 1,200 points he earned for reaching last year’s final are deducted. Adding a potential 2,000 points for winning the tournament would leave Djokovic with a maximum of 5,570 points, fewer than the 5,630 points Nadal has at the start of the tournament.

ATP ranking before the US Open

ATP ranking minus 2021 US Open points