Novak Djokovic says he could potentially “cause more damage” to his body by continuing to compete at the Australian Open following the abdominal injury he sustained during his third-round match against Taylor Fritz. On Sunday the world No 1 returned to beat Milos Raonic 7-6(4), 4-6, 6-1, 6-4. After stating following his match against Fritz on Friday night that the ATP physio had told him his injury was “definitely” a tear, on Sunday he declined to describe his injury in detail. He said he had spent the previous 48 hours doing “different treatments with different devices”, including pills and painkillers, having coordinated with medical staff of Tennis Australia, ATP physios and his own physiotherapist. “It’s kind of a gamble,” said Djokovic. “I mean, that’s what the medical team told me. It’s really unpredictable, you can’t know what’s going to happen with you once you’re on the court. You’re not gonna save yourself or think about going for that point or this shot or that shot. It just pulls you. It’s normal. Playing at this level, you just want to give it all. “It could cause much more damage than it is at the moment, but it also could go in a good direction. So that’s something that I don’t know, and I don’t think I will also know until I stop taking painkillers. As long as I’m with high dose of painkillers, I guess, you know, still can bear some of the pain.” Djokovic said he did not know whether he would play until a few hours before the match but he produced a highly competent performance to overcome Raonic. Although he sometimes grimaced, he won 78% of first serve points, fired 41 winners to just 25 unforced errors, moved smoothly and broke Raonic’s considerable serve three times. “Playing best-of-five with kind of an aggressive mover that I am on the court doesn’t help much with this kind of injury, but I think the combination of pills and treatments and also some willpower and of course certain degree and level of bearing the pain. Mentally I think you have to kind of accept that I did come into the match knowing that I’ll probably feel pain all the way through, which was the case,” said Djokovic. Injuries were the theme of the day as the 21st seed Grigor Dimitrov produced a shock 6-4, 6-4, 6-0 victory against the third seed Dominic Thiem to reach the quarter-finals. Thiem offered little energy or resistance throughout, scoring just six points in the 21-minute third set. Afterwards, he noted physical issues but declined to further elaborate. “Some little physical issues,” he said. “I don’t want to go closer to them. I don’t want to find any excuses. But the thing also is that I’m also not a machine. I mean, sometimes I would like to be, but there are really, really bad days. As soon as you’re not a 100% there on the court on this level, then results like this come up and that’s exactly what happened today.” Dimitrov will face the surprise of the tournament, Aslan Karatsev, a 27-year-old Russian qualifier who defeated the 20th seed Felix Auger Aliassime 3-6, 1-6, 6-3, 6-3, 6-4 to become the first male player in 25 years to reach a grand slam quarter-final on debut.