Home favourite Nick Kyrgios pulled out of the Australian Open with a knee injury the day before he was scheduled to play his opening match.
The Wimbledon runner-up, 27, said he was "devastated" he could not play in Melbourne.
Kyrgios, seeded 19th, was set to play Russia's Roman Safiullin on Tuesday.
"It's obviously been pretty brutal before [one] of the most important tournaments of my career," Kyrgios said. "It hasn't been easy at all."
Considered among the favourites to win the title, Kyrgios "didn't pull up great" from an exhibition with Novak Djokovic on Friday, according to his physio Will Maher.
Maher said they had used the charity event as "a gauge" to see if the player could compete at the highest level.
But afterwards he advised the Australian he would potentially not be able to play a succession of five-set matches over the fortnight.
"He still tried to give himself every chance in the following days to have subsequent training," Maher added.
"But it was clear with each passing session that he was getting sorer and sorer."
Kyrgios, who will be unable to defend the men's doubles title here, will need an operation because of a cyst growing in his meniscus but expects to be fully recovered to play At Indian Wells in March.
"I'm devastated obviously. It's like my home tournament. I've had some great memories here," Kyrgios said.
"Obviously last year winning the title in doubles and playing the best tennis of my life probably. Then going into this event as one of the favourites, it's brutal."
Latest Stories
-
George Twum-Barimah-Adu pledges inclusive cabinet with Minority and Majority leaders
47 mins -
Labourer jailed 5 years for inflicting cutlass wounds on businessman
48 mins -
Parliament urged to fast-track passage of Road Traffic Amendment Bill
48 mins -
Mr Daniel Kofi Asante aka Electrician
49 mins -
Minerals Commission, Solidaridad unveils forum to tackle child labour in mining sector
54 mins -
Election 2024: Engagement with security services productive – NDC
55 mins -
Retain NPP for the good of Ghana – Rebecca Akufo-Addo
56 mins -
‘Let’s work together to improve sanitation, promote health outcome’ – Sector Minister urges
57 mins -
Ellembelle MP cuts sod for six-unit classroom block at Nkroful Agric SHS
60 mins -
‘I’ll beat the hell out of you if you misbehave on December 7’ – Achiase Commanding Officer
1 hour -
AFPNC leads the charge on World Prematurity Day 2024
1 hour -
Court remands unemployed man over theft of ECG property
1 hour -
Election security rests solely with the police – Central Regional Police Command
1 hour -
NCCE engages political youth activists at Kumbungu on tolerance
1 hour -
‘In Mahama’s era students lacked chalk, but are now receiving tablets’ – Bawumia
1 hour