Andy Murray had already spent almost 11 hours on court in the Australian Open before playing Roberto Bautista AgutVenue: Melbourne Park Dates: 16-29 JanuaryCoverage: Commentary every day from 07:00 GMT on BBC Radio 5 Sports Extra 'Tennis Breakfast' live from Melbourne, with selected live text commentaries and match reports on the BBC Sport website & appAndy Murray says he is doing himself "justice" at major events and believes he can still "do some damage" following his Australian Open exit.
Murray finished his second-round match at 4am on Friday and was back playing at Melbourne Park 39 hours later to face the Spanish 24th seed.
"I can have a deeper run than the third round, there's no question," he said.
"I'm competing against a guy ranked 20 in the world and it's still very tight considering the circumstances."
Murray, ranked 66th in the world, needed five hours and 45 minutes to beat Australia's Thanasi Kokkinakis in a thrilling match ending in the early hours of Friday.
That came after the three-time major champion took nearly five hours to win his opening encounter against Italian 13th seed Matteo Berrettini on Tuesday.
After seeing off Kokkinakis, Murray said he managed just three hours' sleep before returning to Melbourne Park to have "seven or eight" blisters on his feet drained.
He was then back on court at 19:00 local time on Saturday to face Bautista Agut, 34, and it was quickly apparent the Scot was struggling to move.
Despite a battling effort, former world number one Murray was unable to reach the fourth round of a major for the first time since 2017.
"There were maybe times in the last year or so where I didn't really feel like I was playing well and I didn't enjoy the way that I was playing," he said.
"The sacrifices and the effort I put in allowed me to get through those matches [against Berrettini and Kokkinakis] and play at a high level that I think was entertaining for the people watching.
"I felt good about the way that I was playing. It's more enjoyable for me when I'm playing like that, when I'm coming into a major event and really believing that I can do some damage."
Murray announced at the 2019 Australian Open that he planned to have hip resurfacing surgery, which he feared would end his career.
After losing to Bautista Agut in the first round, the tournament played a now-infamous retirement video featuring goodbye messages from his rivals.
But, four years later, Murray is still playing and he is upbeat about his chances of a deep run at a major.
"Obviously you never know exactly when the end is going to be," he added.
"I would like to go out playing tennis like this, where I'm competing with the best players in the world in the biggest events and doing myself justice."
Analysis
BBC tennis correspondent Russell Fuller at Melbourne Park
What could Andy Murray achieve in the rest of this year's Grand Slams if he does not need to get up after three hours' sleep - and a 04:05 finish - to have some blisters drained?
Draws can open up, as this Australian Open has shown. Having knocked out Berrettini, Murray's path to the semi-finals would not have contained a single top 20 player - although that is academic now.
Murray took great pride from a screenshot he was sent which suggested he had finished more points at the net than anyone else, although he will know he needs to be quicker to wrap up matches.
I always thought a top 50 ranking would be both a magnificent achievement and the most he could achieve following his two hip operations.
But the way he has emerged from pre-season training, and those three spartan weeks in Florida, means I may need to adjust my sights.
