Emma Raducanu was reduced to tears after being dealt another injury blow ahead of the Australian Open.
The Brit was competing at the ASB Classic in New Zealand against Viktoria Kuzmova, with the score at 6-0, 5-7 when she appeared to turn her ankle and after receiving treatment, she was forced to retire.
Raducanu, 20, ended her 2022 campaign in October due to a wrist injury but has stepped up her training in recent weeks with new coach Sebastian Sachs.
She made a winning start to the year in Auckland earlier this week but was visibly distressed after suffering the latest injury against Kuzmova on Thursday.
It raises concerns over the 2021 US Open champion's involvement in the Australian Open, which gets underway in Melbourne on January 16.
The LTA sent a message to her after her withdrawal, tweeting: "Hope to see you back on court soon Emma."
Speaking earlier this week, Raducanu insisted she was looking forward to a fresh start in 2023 after struggling for form and fitness in the past 12 months.
"My goal is to stay healthy for longer. I'm looking forward to working hard because I've got a better idea of what to expect now, so I'll be less like a deer in the headlights.
"For a results goal I'd say it's to win a title, and three I'd say is to be playing fearless tennis. Just not thinking about consequences, just going for it."
The wrist problem was the latest in a string of issues for Raducanu, who has dropped to 78th spot in the world rankings. She has also been working alongside Andy Murray's former trainer Jez Green in a bid to return to full fitness.
"I think right now, because I'm still trying to find my timing and groove and my tennis, " Raducanu said recently. "But once I settle into that I think the physical side will definitely have made a difference because there's no way it can't have.
"But I'm also not ignorant in thinking two months is going to solve my entire physical condition, it's going to take more time, over a year or two to redevelop."
Raducanu, who was awarded an MBE from King Charles III, had breezed through the first set of the last 16 clash with Kuzmova, leading 6-0 inside 20 minutes.
The Slovakian hit back to win the second 7-5 before Raducanu needed treatment on her left ankle, and she was forced to pull out before the start of the third set.
