EPA/JASON SZENES epa06168720 Jelena Jankovic of Serbia hits a return to Petra Kvitova of the Czech Republic during their match on the first day of the US Open Tennis Championships at the USTA National Tennis Center in Flushing Meadows, New York, USA, 28 August 2017. The US Open runs through September 10. EPA/JASON SZENES

EPA/ANDREJ CUKIC epa08481094 Novak Djokovic (L) and Jelena Jankovic (R) of Serbia react during the pre-tournament exhibition match at the Adria Tour tennis tournament in Belgrade, Serbia, 12 June 2020. The Adria Tour tennis tournaments are to be played in Serbia, Croatia, Montenegro and Bosnia and Herzegovina from 12 June till 05 July 2020. EPA/ANDREJ CUKIC

EPA/JASON SZENES epa06168715 Jelena Jankovic of Serbia hits a return to Petra Kvitova of the Czech Republic during their match on the first day of the US Open Tennis Championships at the USTA National Tennis Center in Flushing Meadows, New York, USA, 28 August 2017. The US Open runs through September 10. EPA/JASON SZENES

EPA/KOCA SULEJMANOVIC epa05146386 Jelena Jankovic of Serbia in action against Carla Suarez-Navarro of Spain during their match for the Fed Cup World Group II tie between Serbia and Spain, in Kraljevo, Serbia, 06 February 2016. EPA/KOCA SULEJMANOVIC EPA/KOCA SULEJMANOVIC

EPA/ALI HAIDER epa04621843 Jelena Jankovic of Serbia reacts during the match against Timea Babos of Hungary during the first round of the Dubai Duty Free Tennis WTA Championships in Dubai, United Arab Emirates, 15 February 2015. EPA/ALI HAIDER