The ATP has announced a revised system for calculating the men's tennis world rankings for when the season resumes.

International tennis halted in mid-March, with Wimbledon being cancelled and the French Open moved to September.

The new rules increase Novak Djokovic's chances of extending his 282 weeks as world number one.

The same tournament cannot be counted twice, so world number two Rafael Nadal will not be able to add to his tally should he successfully defend his US Open and French Open titles later this year - which could reduce his incentive to travel to New York.

The 19-time Grand Slam champion is one of a number of players to have expressed reservations about heading out to the United States. Concerns have been raised about the high rate of Covid-19 infection, the strict protocols which will be in place and the fact the final will take place two weeks before the French Open begins.

However, Djokovic lost in the semi-finals of the French Open and the fourth round of the US Open last year, meaning he could have the chance to boost his tally.

The men's tour is due to resume on 14 August with the Washington Open.

One other change is that this year's singles line up at the ATP Finals will be based on the rankings in early November, and therefore reflect how a player has performed not just this year, but for much of 2019 as well.

This will be to the advantage of last year's eight finalists, and make it harder for players like France's Gael Monfils and Britain's Dan Evans, who were third and 11th respectively in the annual 'Race to London' when tennis was halted.

The WTA Tour is yet to announce how its ranking system will evolve when play resumes in Palermo on 3 August.