Injured Serb star Jelena Jankovic chose not to play in her women's singles clash in the Hopman Cup final against the United States here on Friday.
Jankovic has been battling a thigh injury since Wednesday, but was able to win successive mixed doubles matches in as many days to reach the final with Novak Djokovic.
The 22-year-old was due to play world No.7 Serena Williams in singles in the final, but instead decided to forfeit that match to concentrate on the mixed doubles.
That meant the United States would enter the tie with a 1-0 lead.
For Serbia to clinch the title, Djokovic would have to beat Mardy Fish in the singles, and the Serbs would need to upset the US in the mixed doubles.
Tournament doctor Hamish Osborne said on "Friday Jankovic would not have been capable of playing two matches.
"She will be far better off preparing for the doubles, which is much less strenuous," Osborne said.