Kei Nishikori faces US Open fitness race after positive coronavirus test

Kei Nishikori faces a race against time to be fit for the US Open after revealing he has tested positive for Covid-19.

The 30-year-old Japanese announced on Sunday that he was self-isolating in Florida and as a result had pulled out of the Western and Southern Open, which has been moved to New York from its traditional venue in Cincinnati to act as a warm-up event for the Grand Slam tournament.