British number one Kyle Edmund has pledged to do "everything he can" to be fit for the Australian Open after picking up a knee injury.
The 23-year-old, who is ranked 14th in the world, has withdrawn from next week's Sydney International, which was set to be his final warm-up event before the year's first grand slam in Melbourne.
"I am disappointed that I won't be able to return to Sydney," Edmund was quoted as saying on the Twitter account of the Sydney International.
"I need to focus on my preparations for the Australian Open and do everything I can to be fit for the first grand slam of the year."
Edmund reached the semi-finals of the Australian Open in 2018, losing to Marin Cilic in straight sets, but suffered a shock defeat to Japan's world number 185 Yasutaka Uchiyama on Wednesday in the Brisbane International.
The Australian Open gets under way on January 14.