Due to his visa issues, Novak Djokovic could not defend the Australian Open title this January, staying on nine Melbourne Park trophies. A year ago, the Serb dealt with his rivals and an abdomen injury since the third round.Novak struggled but overcame all the issues to emerge at the top and claim the 18th Major crown. Djokovic experienced an abdomen injury in the third round against Taylor Fritz, taking a medical timeout and struggling in sets three and four before raising his level in the decider.World no. 1 could not train ahead of his next two matches, the crucial ones in his quest. Djokovic’s coach Goran Ivanisevic said he feared the encounters against Milos Raonic and Alexander Zverev the most, as Novak struggled on the return following that injury.Djokovic did not know what to expect against Raonic two days after experie …