Rafael Nadal and Tomas Berdych have secured their places at the ATP World Tour Finals, leaving just two spots in the eight-man field to fill.
Nadal and Berdych will compete alongside Novak Djokovic, Andy Murray, Roger Federer and Stan Wawrinka at the season finale in London from November 15-22.
Nadal qualified for the 11th consecutive season after reaching the semi-finals of the Shanghai Masters, one week on from a runner-up showing at the China Open in Beijing.
The 30-year-old Berdych will make his sixth consecutive appearance at the season-ending event.
In the race for the remaining two places, Japan’s Kei Nishikori and David Ferrer of Spain are currently in seventh and eighth spots.