BBC tennis correspondent Russell Fuller assesses what Novak Djokovic's shock appointment of Andy Murray as coach could mean for both men.

Novak Djokovic cracked a hilarious joke after the news broke out of him adding Andy Murray for the Australian Open as he referenced to one of the Briton's post that came just hours after he retired.

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 ...