(Photo credit: Mike Frey-Imagn Images)
Novak Djokovic has hired a new coach -- longtime friend and rival Andy Murray, who retired from competitive tennis this summer.
Djokovic split with coach Goran Ivanisevic after six years earlier this summer, and he's counting on Murray to help him prepare for the Australian Open, which begins Jan. 14 in Melbourne.
"We played each other since we were boys. Twenty-five years of being
