The mystery surrounding Jannik Sinner's physical condition continues. The world number one tennis player has returned to the J Medical clinic in Turin, where he is expected to undergo new checks and tests on his right knee.

The injury forced the Italian to withdraw from the US Open, while a few days ago Sinner stated that he was sad and disappointed, emphasizing that he still needs time to recover.

The 25-year-old's last competitive match was the Wimbledon final, after which he has not returned to the court. So far, there has been no official communication on the exact nature of the injury, or when it was sustained.

The suspicions have been further heightened after a video of Sinner training was released. The footage was released on the same day he announced his withdrawal from the US Open, fueling fresh speculation.

Now, all eyes are on the tests in Turin and the answer they will give for the world number one's return to the field.