One week ahead of the opening slam of the season, the world number four and one of the favourites has picked up an injury that could hamper his chances.
Alexander Zverev is a major doubt for the Australian Open after suffering a hamstring injury at an exhibition event in Adelaide.
Zverev is fourth-favourite for the first grand slam of 2019 after finishing last year fourth in the world rankings, his season ending with the ATP Finals crown in London and back-to-back victories over Novak Djokovic and Roger Federer.
The German was in fine spirits as he partnered Angelique Kerber at the Hopman Cup last week – the duo losing the final to Switzerland's Roger Federer and Belinda Bencic.
However, his chances in Melbourne have been dealt a huge blow with the news he pulled his hamstring during practice on Monday.
Speaking to the crowd at the World Tennis Challenge, Zverev said he intends to get plenty of rest to ensure he is fit to feature at Melbourne Park next week.
The draw for the Australian Open will take place on Thursday.