Novak Djokovic is likely to face one of his most challenging tests yet in his bid to win his 25th Grand Slam at the Australian Open in January.

The Serbian is a 10-time winner of the event Down Under and last won the tournament in 2023. But with Jannik Sinner's emergence as the top men's player and Carlos Alcaraz adding another two Majors to his collection, it suggests Djokovic's reign of dominance may coming to an end.

The final update of the ATP rankings for 2024 was released on Monday with Sinner listed as the undisputed world No 1. His haul of 11,830 points - 3,915 more than closest challenger Alexander Zverev - means it will take a few months at least before anyone is able to remove him from the summit.

Zverev has risen to No 2 after making it to the last four of the ATP Finals, with Carlos Alcaraz in at third. US Open runner-up Taylor Fritz has risen to fourth, with Daniil Medvedev behind him and Casper Ruud in sixth.

Djokovic has fallen to No 7 - his lowest year-end rank since 2017 when he was 12th - and the 37-year-old will consequently face a stiffer test in Melbourne.

His drop in the rankings can be attributed to some ill-timed injuries, which forced him to miss the ATP Finals in Turin. Additionally, his failure to win any Grand Slam in a calendar year for the first time since 2018 and his gold medal in the Paris Olympics, for which he did not collect any rankings points, may have had an effect.

Now that Alcaraz has fallen to No 3, it means that the Spaniard could feasibly be on the same side of the draw as Sinner in Australia. If he was ranked second, this wouldn't have been possible.

In Grand Slam draws, the top two seeds are always separated to go on opposite sides of the draw before the rest of the players are selected at random. This ensures that fans have a chance to see the top two players in the final, provided that they win their matches en route.

For Djokovic, there's a heightened possibility that he would have to face and/or Alcaraz or Sinner before getting to the final, assuming he makes it to the latter stages.

The prospect of facing both Sinner and Alcaraz in the same tournament will be a concern, particularly given Djokovic's recent head-to-head record against the pair.

Alcaraz has beaten Djokovic in the last two Wimbledon finals, while Sinner has won the last three encounters with the veteran star in Shanghai this year, as well as the Australian Open and Davis Cup in 2023.

All will be revealed in a few months' time when the Australian Open main draw is decided the week before the event begins on January 6.