Novak Djokovic of Serbia hits a return against Andreas Seppi of Italy during their fifth session men's singles match on day three of the Hopman Cup tennis tournament in Perth. AFP/Tony Ashby
Djokovic had wrapped up a 6-3 6-4 victory over Italian Andreas Seppi when the incident happened. The
Serb left his racquets and bag on the court and limped straight up the players tunnel to receive a medical assessment in the locker room.
Djokovic was unable to complete a television interview he had agreed to after his victory over Seppi.
Djokovic only arrived in Perth from Abu Dhabi late on Sunday and said he was troubled by jet lag.
"I felt this morning that I was dream-walking," he said.
"I broke the ice after the first set and started to feel better."
Djokovic and Ana Ivanovic held an unassailable 2-0 in the tie against the Italian pairing of Seppi and Francesca Schiavone.
Ivanovic had begun the day by beating Schiavone 6-0 6-4.
Djokovic is taking part in the round-robin teams event to be guaranteed at least three matches in his build-up to the Australian Open, which begins on January 14.