Kei Nishikori a doubt for US Open after second positive coronavirus test

Former world number four Kei Nishikori looks set to miss the US Open after a second positive test for coronavirus.

Former world number four Kei Nishikori looks set to miss the US Open after a second positive test for coronavirus.

The Japanese announced he had Covid-19 earlier this week, forcing him to withdraw from the Western and Southern Open in New York, but a second test shows he still has the virus.