KEY POINTS:
- Rafael Nadal had to receive medical attention during his second-round clash.
- The Spaniard at one point was seen grabbing at his hip.
- But he finished the match, saying he "didn't want to leave the court with a retirement".
A gracious Rafael Nadal has refused to blame his shock loss to American Mackenzie McDonald all on injury as the legendary Spaniard's Australian Open title defence came to an abrupt end.
Nadal grabbed at his left hip during the eighth game of the second set of his second-round clash, immediately going off court for medical attention.
The 36-year-old resumed playing on Rod Laver Arena but was clearly in pain and struggling to run as world number 65 McDonald closed out the biggest win of his career 6-4 6-4 7-5.
Even before the injury, Nadal was rattled by McDonald, who broke serve in the opening game of the match and was confidently outplaying the defending champion.
"This word 'if' I don't like a lot because 'if' in sport or in life in general don't make a lot of sense," Nadal said.
"In the end, I am out of the tournament and he's in the third round, so well done for him.
"He was playing at a great level of tennis. Life continues for me."

World number 65 Mackenzie McDonald praised Nadal's resilience, admitting he was thrown out of "rhythm" by the gritty left-hander playing differently due to the injury. Source: AAP, SIPA USA / USA TODAY Network
After the loss, Nadal slowly walked off court and made extra time to acknowledge the crowd in what could be his final appearance at Melbourne Park.
Despite winning two majors last year, Nadal entered this tournament out of form, and has now lost seven of his past nine singles matches.
The hip problem marks the sixth time in his grand career that either injury or illness has cruelled a campaign at Melbourne Park.
He retired in the 2010 quarter-finals against Andy Murray with a knee injury and was badly hindered by a hamstring strain the following year in a last-eight loss to countryman David Ferrer.
Nadal withdrew from the Open in 2013 with a stomach virus and suffered a back injury in the warm-up before losing the 2014 final to Stan Wawrinka.
In 2018, the great Spaniard quit his quarter-final against Marin Cilic with a hip issue.

Rafael Nadal at a post-match press conference. Source: AAP, SIPA USA / Cal Sport Media
"I consider all the time stopping, but I didn't ask the physiotherapist at the end," he said.
"I am old enough to make my own decisions.
"I didn't want to retire, to be defending champion here.
"I didn't want to leave the court with a retirement. Better like this at the end. I lost.
"Just try your best until the end."
Nadal last year finally won a second Australian Open title, 13 years after his first, by coming from two sets down to defeat Russian Daniil Medvedev in a classic decider.
The men's world number two's early exit is another blow for Australian Open organisers, with the draw already ravaged by major withdrawals and retirements.
, , her sister Venus, , world number one Carlos Alcaraz and the legendary Roger Federer are all missing.
Tennis Australia boss Craig Tiley was captured with a grim look on his face during Nadal's medical timeout.
McDonald praised Nadal's resilience, admitting he was thrown out of "rhythm" by the gritty left-hander playing differently due to the injury.
"He's an incredible champion," the 27-year-old said.
"He is never going to give up regardless of the situation."