Novak Djokovic and Stan Wawrinka are set to return to the court at the Mubadala World Tennis Championship in Abu Dhabi in December.
Former world number one Djokovic curtailed his season prematurely after an elbow injury forced him to retire from his Wimbledon quarter-final against Tomas Berdych in July.
The 12-time grand slam champion will return before the year is out, though, having agreed to join Rafael Nadal, Dominic Thiem, Milos Raonic and Pablo Carreno Busta for his fifth outing at the exhibition tournament.
"I am extremely excited to return to Abu Dhabi for the fifth time and take part in the 10th edition of the Championship," said Djokovic in a statement.
"It is a huge honour to take part in such a special tournament. The line-up is very strong as always and it will be the perfect way to make my comeback and begin the season.
"Abu Dhabi is an amazing place and this is going to be a great event for all of the fans."
Wawrinka will also make his comeback in Abu Dhabi having opted to undergo knee surgery in August rather than defend his US Open title.
"It is always a pleasure to kick the season off at the beautiful event in Abu Dhabi," said Wawrinka, whose last appearance was a first-round Wimbledon loss to Daniil Medvedev.
"The fans are amazing there and the draw is as strong as always with a lot of great players. My recovery is going well and I can't wait to be back on court.
"I'm working hard together with my team and looking forward to being back."