Bad Knee to Keep Isner Out of Australian Open
World number 13 and top-ranked American John Isner has withdrawn from next week’s Australian Open with a knee injury, leaving 22nd-ranked Sam Querrey as the highest-ranked U.S. man at the season’s first Grand Slam tournament. Isner, who spent 18 weeks in the top 10 before finishing last year at 14th, injured his knee at the Hopman Cup…

