Novak Djokovic will open the U.S. Open without a competitive match since Wimbledon, a risk he's willing to take after banking "a lot of training in last three, four weeks" and reshaping his priorities around the four majors.

Novak Djokovic believes there is "room for improvement" regarding the prize money available to players at the four Grand Slams.

Tennis star Novak Djokovic has expressed reservations about the adequacy of Grand Slam prize money, even as the US Open unveiled a record-breaking $90 million prize pool representing a 20 per cent increase from the previous year.