Novak Djokovic says he will test his problem elbow at an exhibition before deciding whether to play. Asian number one Nishikori has not played competitively since last August after suffering a torn tendon in his right wrist during a practice session at Cincinnati. He said he still wasn't ready for a gruel ling Grand Slam campaign.

"I am very sorry to announce that I will miss the Aussie Open this year," he said on his website of the opening major of the year, starting in Melbourne on January 15. "The Aussie Open is my favourite Slam, it's my 'home' Slam," he added.

"It's the Slam that takes incredible care of the players and their teams, and it hurts that I will have to miss it this year. My rehab is going well but I am just not ready 100 percent to come back yet in best of five set matches."

"Novak is travelling to Australia where he will take part in two exhibition tournaments," said a statement on 12-time Grand Slam winner's website early today. "After the two events, the decision will be made about his participation at the first Grand Slam of the season, the Australian Open, where 'Nole' has been crowned champion six times."