In a tight race to qualify for the ATP World Tour Finals, Kei Nishikori is playing through a leg injury this week. The world No. 7 received treatment on his back and legs during his second-round match in Tokyo, where packed crowds have turned up to see the U.S. Open finalist. But the Japanese, who withdrew from doubles, says he is playing the tournament for London, not for Tokyo.

“The ‘cool’ answer would be to say I was doing it for the sake of Japan, but the truth is I want to play in London and I want the 500 points on offer here,” he said.

Nishikori and five other players between No. 6-11 are within a few hundred points of each other. Eight players qualify for the season-ending round-robin event.

Nishikori, who had twice withdrawn from matches with injury this season and did not play the two Masters events before the U.S. Open because of a foot problem, said he could not do more damage to the muscle by competing. “It's not the kind of injury that's going to keep me from playing,” he said.