Novak Djokovic cut short a practice match against Daniil Medvedev on Wednesday as a hamstring injury lingers ahead of the Australian Open.
Record nine-time Melbourne champion Djokovic is back in Australia after he was denied entry last year and subsequently deported due to his COVID-19 vaccination status.
The 21-time major winner is expected to be a contender again at the first grand slam of the 2023 season, but his preparations were hampered by an injury scare on Wednesday.
Djokovic, who won his first title of the year in Adelaide last week, was able to complete only a single set of an exhibition against Medvedev.
"It's a hamstring that I had problems with in Adelaide actually last week," he explained to Nine's Wide World of Sports. "It was against Medvedev, when I played the semi-final, and I played with him today in a practice match.
"I just felt it a bit, pulling, and I didn't want to risk anything worse. I played a set, apologised to him, and he was understanding.
"I just want to avoid any bigger scares before the Australian Open."
Having required a lengthy medical timeout against Medvedev in Adelaide, Djokovic had described the issue as "nothing too serious".
The Serbian is also scheduled to play a practice match against home hopeful Nick Kyrgios this week.