Despite his on-court dominance, Jannik Sinner has been the target of significant abuse from a select group of his ATP colleagues – this time however, it’s nothing to do with his doping saga.

The serene glide to a maiden US Open title in the middle of two Masters trophies has coincided with the Italian’s most challenging moment of his career.

After Jannik Sinner twice tested positive for the banned substance clostebol in March, he was initially cleared of any wrongdoing in a statement announced by the International Tennis Integrity Agency mere hours after clinching the title in Cincinnati two months ago.

Since however, the criticism has been piled on the world number one. While he has lost just once since the news broke, Sinner admitted he’s faced a lot of pressure this season.

During his Beijing Open campaign, the World Anti-Doping Agency (WADA) announced they were appealing the case and re-opening it immediately. They called for the Italian to face a ban of at least one year – Sinner responded at the time saying he was ‘surprised’ at the new ruling.

With all this furore and speculation, an ATP colleague has now taken aim at the world number one for his comments on the tennis calendar – a topic that’s been hotly debated on and off since the Paris Olympics.

A scheduling grievance Iga Swiatek first aired, a packed summer of tennis has been even more unrelenting and controversial than usual.

With the Olympics taking place on the clay-courts during a time when players are normally given the chance to transition from grass to the hard-courts, many on the circuit were concerned about the stress it would put on their bodies – several high-profile players even skipped the Olympics as a result.

A packed calendar saw Carlos Alcaraz claim the ATP were trying to ‘kill’ the players in what was a statesmen brassy in keeping with the general mood.

In shocking contrast to the Spaniard and Swiatek however, Sinner contradicted that point of view, suggesting that players should be able to manage the calendar more carefully and can ‘choose’ when to play.

France’s Ugo Humbert has bit back, suggesting the Italian has totally misread the situation. “I hear some people, like Jannik Sinner, say that you can choose not to play, but they are not thinking clearly,” the world number 16 told Punto de Break.

“When you are ranked 50 or 60 in the world, you try to play as much as you can to climb in the rankings. Things need to be reconsidered, try to condense them a bit more because the way things are right now, it’s exhausting. After a while, it’s simply not possible,” he concluded.

With Humbert certainly not the only player ready to raise this issue, it has once again come just after the Frenchman featured at the Ultimate Tennis Showdown exhibition event – extra time on court that a seemingly weary player would surely look to avoid.

When Alcaraz and Alexander Zverev criticised the ATP calendar, it felt increasingly difficult to take seriously due to their insistence on appearing at a somewhat pointless exhibition event.

Zverev was battling a serious health condition while playing at the Laver Cup, yet felt it suitable to complain over scheduling – surely just take the week off!

Sinner, who chose not to play at the Laver Cup, has managed this minutes far more wisely, and yet has still managed to play over 70 matches this year.

The Italian has even featured at the Six Kings Slam – a new exhibition event in Saudi Arabia – despite dealing with a busy schedule.

While broadly the calendar is teetering on dangerous for players and has caused a rise in injuries, it feels strange to criticise the schedule while playing events you do not have to.