The Mubadala World Tennis Championship is currently taking place in Abu Dhabi and GiveMeSport is streaming live coverage on their Facebook page.
A host of global tennis stars - including Rafael Nadal and Stan Wawrinka - are taking part in the exhibition tournament which has been held annually since 2009.
Novak Djokovic, 30, was due to make his comeback on Friday against Spain's Roberto Bautista Agut after almost six months on the sidelines - but pulled out at the last minute due to an elbow injury.
The Serbian former number one hasn't played since retiring from his Wimbledon quarter-final defeat to Tomas Berdych in July.
British tennis star Andy Murray has stepped in to replace Djokovic and will face Bautista Agut instead.
“I am terribly disappointed that I am forced to withdraw from the Mubadala World Tennis Championship," said Djokovic in a statement on his website.
"Unfortunately, in the past few days I started to feel pain in the elbow and after several tests, my medical team has advised me not to risk anything, to withdraw from the tournament and to immediately continue with the therapies.
“I am very sad because I was eager to return to playing official matches. I enjoyed the practices and everything I did to get ready for the start of the season, including the tournament in Abu Dhabi, where I always enjoy playing.
"Now I need to accept this situation, and to wait for the results of the therapies, in order to start playing tennis again and getting back to full rhythm. This might affect the start of the season and the tournament plan, but the decision will be made in the following days.”
Djokovic, now ranked at 12 in the world, will still hope to take part in the upcoming Australian Open.
Asked about his goals earlier this week, Djokovic told Sport360: "I would not be honest, not to you, to myself, if I tell you anything less than being No. 1 and winning Slams.
"For these circumstances now that I am in, I'm trying to balance these goals, at the same time be a bit more understanding of what's going on here and say just take your time. Even if it doesn't happen next season or whatever, take your time.
Catch a live stream of the Mubadala World Tennis Championship over on GiveMeSport's Facebook page.