The Association of Tennis Professionals (ATP) has announced that there will be an adjustment in how the world rankings are calculated once international tennis resumes, due to the COVID-19 pandemic.
The governing body for men's tennis will now extend the period in which points will be calculated for players when competition returns in August.
Traditionally, the rankings are based on the best 18 results over a year, but it will now cover a period of 22 months from March 2019 to December 2020 in light of the disruption caused by the outbreak of the virus.
The rankings have been frozen since March 16, just days after the ATP Tour was suspended due to the pandemic.
Now, its revised system will aim to deliver "flexibility and fairness" to players at all levels due to the condensed provisional 2020 calendar.
It will give stability to players who cannot or would prefer not to compete for the rest of the year due to safety measures, it is hoped, as well as allow the system to be adapted if necessary.
Britain's three-time Grand Slam champion Andy Murray is among players who had asked for a two-year ranking system.
Of a player's top 18 results, two editions of the same tournament will not count towards their points – for example, if an athlete competes at the 2019 and 2020 French Open, only their best result will count.
Points that are added from 2020 competitions will remain on a player's ranking for 52 weeks, or until the event is played again in 2021.
Further adjustments will be made if the 2021 season is also affected.
The tennis calendar has been heavily hit by the COVID-19 pandemic, with the three remaining 2020 Grand Slams all impacted.
Wimbledon was cancelled for the first time since the Second World War, while the French Open has been moved to new dates in September and October.
The US Open will begin next month as planned, but behind closed doors.