Serena Williams has been forced to withdraw from her Eastbourne semi-finals later on Thursday after doubles partner Ons Jabeur suffered a right knee injury.
Williams, 40, will now concentrate on preparing for Wimbledon, where she has been awarded a wild card.
When Williams announced a shock return to tennis on June 14, it put an end to retirement rumours after long-term coach Patrick Mouratoglou started to work with Simona Halep earlier this year.
A wild card entry into the doubles at Eastbourne was agreed to give the seven-time Wimbledon champion some match practice before she begins her latest pursuit of a 24th Grand Slam title.
The American has played her first two competitive matches at the Rothesay International since limping out of Wimbledon in tears last summer with a hamstring problem.
Williams and Ons Jabeur made it through to the semi-finals with a narrow victory over Maria Bouzkova and Sara Sorribes Tormo and then a more convincing one against Shuko Aoyama and Chan Hao-ching.
Tunisian Jabeur, ranked third in the world in singles, has injured her right knee, the LTA confirmed in a social media post.
Speaking after Wednesday’s match, Williams said: “I feel good, as good as one can feel after having such a long time off. I was telling Ons, this was a really good match and the second set in particular, they played really well, but we were able to just play different circumstances.