Doubts have been raised about Novak Djokovic’s condition heading into the US Open with fresh footage appearing to show him continuing to struggle with a thigh injury. The 24-time major winner has been battling with the problem over the past few months, and it has severely impacted his preparations for the final Grand Slam of the season.

Djokovic opted against competing at any warm-up tournament heading into the US Open, which included skipping the Cincinnati Open, as he has been trying to recover from a problem with his thigh.

He has not featured since suffering a straight-sets defeat at the hands of Jannik Sinner at Wimbledon over a month ago, and there are now fears that he may not be back to his best ahead of battling it out at Flushing Meadows.

The Serb is currently practicing in Montenegro ahead of the competition, and some secretly-snapped footage of one of his sessions has been shared online. In the video, a physio could be seen working on Djokovic’s thigh whilst he gingerly stood leant up against the back of the court.

After the brief treatment, the 38-year-old then completed some half-hearted serves, which led some of Djokovic’s supporters to fear that the world No. 7 is not fully fit and ready to go to battle at the US Open.

He is set to join forces with fellow Serbian Olga Danilovic on Tuesday to compete in the new-look mixed doubles. The pair will face Mirra Andreeva in the first round of the competition, which could set up a clash with Emma Raducanu and Carlos Alcaraz, if they are able to see off the challenge of top seeds Jack Draper and Jessica Pegula.

Djokovic is not the only player currently practicing in Montenegro ahead of the US Open, with Luka Pavlovic also being put through his paces there as well. The latter shared a picture of the duo standing with their arms around each other following a practice session.

Pavlovic captioned the post: “It's an honour and a privilege to be preparing for the US Open with the greatest tennis player of all time! Thanks for a great week.” The Frenchman will be hoping that the chance to work with an all-time great will have helped him up his game as he looks to make his mark in the United States.