Emma Raducanu withdrew from her match against Naomi Osaka as Great Britain started their United Cup campaign with a 2-1 group-stage win against Japan in Australia.
The British number one has not played since October and pulled out of two exhibition matches in the United States in December because of a minor foot issue.
Her withdrawal against Osaka in Perth comes in the lead up to the Australian Open, which begins in Melbourne on January 18.
Raducanu has struggled for form and fitness since winning the US Open in 2021, but last season, completed 50 matches for the first time in her career and is 29th in the women's rankings.
Despite Raducanu's absence, Great Britain managed to beat Japan and will face Greece in their other Group E tie tomorrow.
