Jannik Sinner is undoubtedly missed on the ATP Tour, having last played a match in mid-July.

That just happened to be the final of Wimbledon, where he defeated Alexander Zverev to claim his fifth career Grand Slam title. Since then, however, the Italian has been completely absent because of a knee injury, which forced Sinner to end his season earlier this month.

Many tennis fans were expecting to see him in action after Wimbledon, but the current world number one continuously withdrew from event after event because of his knee issue. That included the US Open and the ongoing Vienna Open.

However, while the 25-year-old has called time on his 2026 ATP season, it appears that he will make an appearance elsewhere before the year is out. And that commitment to the Six Kings Slam certainly leaves Sinner open to criticism.

Jannik Sinner open to criticism after Six Kings Slam decision

Sinner was in the initial field for the Six Kings Slam in October, but was replaced by Learner Tien because of his knee injury. But the tournament has since been pushed back to December, and the Italian has returned to the lineup.

Sinner is in the field for the exhibition in Riyadh at the end of the year, alongside fellow ATP superstars Carlos Alcaraz, Novak Djokovic, Alexander Zverev, Alex de Minaur and Taylor Fritz. It is scheduled for December 27-30.

And while players leave themselves open to criticism for playing in such events despite often complaining about the busy calendar, Sinner is especially vulnerable this time around. He is clearly injured, but at the same time will clearly be recovered in time for the Six Kings Slam. However, it’s not a great look to skip so many ATP events and officially close down your season, before taking on an exhibition in the same calendar year.

Of course, it’s fair to say that there is a major financial incentive for such participation. Each Six Kings Slam player received $1.5 million for simply taking part in 2025, with the champion awarded a further $4.5 million.

And Sinner knows about those extraordinary figures more than any other player, having won both of the editions of the Six Kings Slam so far. He has beaten Alcaraz in both finals, with another rematch perhaps the only positive many fans can take from his upcoming appearance. After six ATP clashes in 2025, Alcaraz and Sinner met only once in 2026.

The Italian is really missed on the ATP Tour, arguably more so by fans than his rivals. And along with leaving himself open to criticism with this decision, he also risks causing further damage to his knee. And that would be a disastrous outcome for Sinner, who should be doing all he can to return to 100%.