No. 1 American John Isner Withdraw From Australian Open

John Isner, the highest-ranked American men’s tennis player, pulled out of the Australian Open starting next week because of a knee injury.

Isner, who was seeded 12th at the season-opening Grand Slam tennis tournament in Melbourne, lost his opening round match yesterday at the Sydney International 6-4, 6-4 to compatriot Ryan Harrison. Afterwards, he told reporters he’d been struggling with a bone bruise on his knee.

“Doctors have told me that continuing to play on the knee could result in a more serious injury,” Isner said today in comments released by Australian Open organizers.

The two-week tournament starts Jan. 14.

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