Emma Raducanu was forced to retire hurt from her second-round match at the ASB Classic in New Zealand after rolling her ankle 11 days before the start of the Australian Open.
The British number one, 20, had won the opening set 6-0 against Viktoria Kuzmova in Auckland but lost the second 7-5.
Raducanu called for medical treatment before the start of the third set, and just two points into her service game it became apparent she could not continue.
Raducanu ended her 2022 season early after suffering a wrist injury in October, but had started 2023 by rallying for a 4-6 6-4 6-2 victory over emerging Czech talent Linda Fruhvirtova, 17, on Tuesday.