Six-time champion Novak Djokovic has not played since withdrawing from Wimbledon with an elbow injury. He also withdrew from the Abu Dhabi exhibition event and the Qatar Open which will leave him, like Nadal, with no match practice in 2018 should he play the Australian Open. Similar to Nadal, he appears doubtful however is scheduled to play in two exhibition tournaments, the Kooyong Classic and the Tie Break Tens. Djokovic has developed into one of the world's strongest players when at full fitness. However, not only is he battling an injury but his mental strength has been called into question and should he play the Australian Open, he will face a tough time advancing past the fourth round.
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