Heartbreak and disbelief as Murray announces retirement

Tennis ace Andy Murray's tearful announcement Friday that he'll be forced to retire this year prompted a volley of tributes to the man, fond recollections of a historic career and encouragement to serve up a fitting farewell.

American star Andy Roddick led the tributes to the former world number one, describing his 11-time opponent as an "absolute legend" who is on the "short list of best tacticians" in the history of the sport.

"Unreal results in a brutal era. Nothing but respect here. I hope he can finish strong and healthy," he said.

Murray's failure to recover from a long-term hip injury has put his dream to win next week's Australian Open almost beyond reach.

Such is the level of pain that there is speculation he may not be able to go the distance, much less set up a dream farewell at Wimbledon this July.

Argentina's Juan Martin del Potro -- who fell short against Murray in a memorable 2016 Olympic gold medal game -- urged him not to throw in the towel.

"Andy, just watched your conference. Please don't stop trying. Keep fighting," he wrote.

"I can imagine your pain and sadness. I hope you can overcome this. You deserve to retire on your own terms, whenever that happens. We love you @andy_murray and we want to see you happy and doing well."
"Your greatest impact on the world may be yet to come. Your voice for equality will inspire future generations."