Novak Djokovic is concerned about the long-term damage on his body after playing through the pain barrier to beat Milos Raonic in the Australian Open last 16. (More Sports News)
The world number one has been struggling with a "muscle tear" that made him consider whether to withdraw from the tournament.
But the defending champion withstood everything Raonic threw at him in a four-set match on Sunday to remain on course for a record-extending ninth Melbourne crown.
Djokovic is unable to train between matches but is hoping painkillers can help him through the tournament, with Alexander Zverev up next in the quarter-finals.
"In my head it is now all about recovery. I'm not thinking about training – I just want to feel better and better as the tournament progresses," he told Eurosport.
"Because I'm on strong painkillers for 48 hours, I don't know the damage that is being done [to my body]."
DJOKOVIC BRINGS UP MILESTONE WIN
A day that started with uncertainty over whether Djokovic could even take to the court ended with the Serbian celebrating a milestone victory in Melbourne.
The 33-year-old continued his dominance over Raonic with a 12th win in a row against the Canadian to bring up his 300th grand slam match win.
After progressing 7-6 (7-4) 4-6 6-1 6-4, Djokovic hopes to use the next couple of days to rest up ahead of taking on Zverev.
"If it was any other tournament than a grand slam I would have withdrawn, that's for sure," he said. "I didn't know before I finished my warm-up today, a few hours before the match, whether I would play or not.
"When I warmed up I was fine. During the match it was a bit on and off. It's not ideal but I can't complain. I won against a great player and hopefully it will be even better in two days.
"I didn't have much preparation for this match and didn't hit a tennis ball since two nights ago since last match point. It's a grand slam and at this stage in my career it means everything. There are four grand slams in a year and I give everything to win."
Sixth seed Zverev beat Dusan Lajovic 6-4 7-6 (7-5) 6-3 earlier on Sunday, bringing up a landmark 50th grand slam match win of his own, and is relishing the prospect of facing Djokovic.
"You've got to play your best tennis to have a chance, especially here," said Zverev, who has yet to drop a set. "This is Novak's favourite court, his favourite tournament.
"To be able to have a chance against him, you have to be playing extremely well. You have to be playing aggressive tennis, being the one that dominates. I'm looking forward to the challenge. I think it's one of the toughest challenges in our sport."
THIEM STUNNED BY DIMITROV
Dominic Thiem said he is "not a machine" after his hopes of reaching back-to-back finals at Melbourne Park were dashed by Grigor Dimitrov.
The US Open champion was stunned 6-4 6-4 6-0 by Dimitrov, who tallied 18 unforced errors to his opponent's 41 in a match lasting just over two hours.
Thiem came through a gruelling five-setter against Nick Kyrgios on Friday and put his exit at the hands of Dimitrov down to a combination of physical factors.
"The thing is, I'm not a machine. I mean, sometimes I would like to be, but there are really, really bad days," explained Thiem, who lost to Djokovic in last year’s final.
"I think it was down to a combination of some things, some little physical issues, plus a real bad day, plus the fact that he's a great player. A result like that can happen."
Dimitrov is into the Australian Open quarter-finals for a fourth time, extending his record for most last-eight appearances by a Bulgarian player – male or female.
KARATSEV'S FAIRYTALE RUN GOES ON
Awaiting Dimitrov in the next round is qualifier Aslan Karatsev, who also pulled off a surprise result in recovering from two sets down to beat Felix Auger-Aliassime.
The world number 114 followed up his victory over eighth seed Diego Schwartzman in the previous round with a 3-6 1-6 6-3 6-3 6-4 success.
In doing so, the 27-year-old becomes the first man to reach a major quarter-final since Romania's Alex Radulescu at Wimbledon in 1996.
And the tournament's surprise package, one of three Russians to have reached the last 16 this year, is now looking to keep his incredible run going.
"I'll be ready for everyone," Karatsev said. "It's amazing, amazing. It was a big win from two sets down and emotionally it was tough.
"I am trying to focus more on the tournament, on the matches than record. It's a good feeling... it's impressive, but I was working a lot, and it just happened right now."
