Former world number one Novak Djokovic's preparation for next month's Australian Open suffered a blow after he pulled out of the season-opening exhibition event in Abu Dhabi on Friday due to pain in his right elbow.
The 12-time grand slam winner was scheduled to kickstart the new season against Roberto Bautista Agut but was advised by his medical team to skip the tournament just hours before the match.
Djokovic has not played since he was forced to retire against Tomas Berdych in the quarter-finals of Wimbledon in July due to an elbow injury.
"I am terribly disappointed that I am forced to withdraw from the Mubadala World Tennis Championship," the Serb said in a statement.
"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. 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."
Organisers said that Britain's Andy Murray had agreed to step in and play an exhibition match against Bautista Agut instead. Murray has been out of competitive action for six months due to an ongoing hip problem but was in Abu Dhabi as part of his rehabilitation.
The Australian Open, the first grand slam of 2018, begins on Jan. 15 at Melbourne Park.