A "gutted" Thanasi Kokkinakis is out of the Australian Open men's singles due to injury.
The 20-year-old was a late withdrawal from the Sydney International with an abdominal strain and has not been able to recover in time for the Open starting on Monday at Melbourne Park.
Kokkinakis had been poised to make a long-awaited singles comeback after enduring shoulder, pectoral and groin injuries during a 15-month stretch on the tour sidelines.
"Absolutely guttered (sic) to withdraw again from the best tournament in the world @AustralianOpen ... just can't seem to get my body right #soon," Kokkinakis posted on Twitter on Friday.
Kokkinakis would have been able to play with an injury-protected ranking of 81 if he had recovered in time for the Open.
Tournament director Craig Tilley confirmed the South Australian would be replaced by a "lucky loser" from the qualifying draw.
Local wildcard Omar Jasika said it had been a hard pill to swallow for Kokkinakis after such a long absence.
"I talked to Thanasi this morning and he wasn't too happy," Jasika told AAP.
"He was a bit upset because he really wanted to play in this year's Aussie. But what can you do. You've got to look after your health most importantly. Hopefully he's back soon."
Fellow Aussie Nick Kyrgios took to Twitter to express sympathy for his good mate.
"Tennis isn't the same without him around," he posted.
It is unclear whether Kokkinakis will still play in the doubles at the Open.
Kokkinakis' career has stalled since 2015, when he bettered Bernard Tomic in a memorable five-setter then lost to Novak Djokovic at the French Open.
The ATP event at Indian Wells in March appears the next most likely tournament for him to re-launch his singles career.