 Novak Djokovic has opened up on the extent of his hamstring injury as he admitted it was really bad during his third-round win over Grigor Dimitrov. The fourth seed needed a medical time out but prevailed 7-67 6-3 6-4 and later confessed that he had almost been forced to pull out of the Australian Open ... Djokovic feeling really bad sparking doubts over Aus Open... 