Dan Evans limped off court after retiring from his Erste Bank Open match against Frances Tiafoe with a serious-looking calf injury – four weeks before the Davis Cup Finals.
The British number two was leading 4-1 in the first round when he pulled up sharply at the baseline.
Evans, 33, looked forlorn as he received treatment and it soon became clear he would be unable to continue.
On Monday, Evans was named in Britain’s team for next month’s Davis Cup Finals.
Evans was instrumental in helping his nation qualify for the knockout stage of the men’s team event and will be hoping the injury is not serious enough to rule him out.
Britain take on Serbia in the last eight on 23 November, with the semi-finals and final taking place later that week in Malaga.
Evans was in total command against American world number 14 Tiafoe in Vienna when he appeared to pop his right calf muscle attempting to sprint forward from the baseline.
The world number 35 had dominated on serve and troubled the out-of-sorts Tiafoe with his clean returning, taking one of four break points before looking to further close in on the opening set.
But early in the sixth game, Evans let out an anguished cry as he spun around in pain and shock.
Immediately hopping towards his chair, Evans signalled for treatment and the gravity of the injury left him visibly frustrated.
The Briton appeared to tell the physio he could not walk and within moments it was obvious he would not be able to continue.
