Serena Williams' readiness for the Australian Open has hit a damage obstacle, with the world No1 hauling out of Monday's Hopman Cup matches due to a knee issue.
Williams was because of face Ukraine's Elina Svitolina in America's opening tie of the blended groups competition as she started her 2016 crusade.
The 34-year-old rehearsed on the Hopman Cup courts at Perth Arena on Monday morning before pulling back from her booked match refering to knee aggravation.
Williams, who was supplanted by world No87 Vicky Duval, was sure she would have the capacity to play the following tie against the Australia Gold group of Lleyton Hewitt and Jarmila Wolfe on Tuesday evening.
Last November, her mentor Patrick Mouratoglou uncovered Williams was managing comparative knee issues to those that have hampered Rafael Nadal's profession as of late.
"It's simply playing for such a variety of years, the ligament is [almost] gone," Mouratoglou said at the time.
"Not every last bit of it, but rather a major part, so the bones simply hit themselves. She has bone wounds, and on the off chance that you continue playing with this for a really long time, excessively, the following step is an anxiety break."
Nadal has spent long spells on the sidelines with his knee issues.
Williams had just about two months off after the US Open before coming back to the practice courts in November.
She touched base in Perth on Saturday, and there were no indications of a harm worry before she hauled out on Monday morning.