Novak Djokovic is relishing his return to tennis after being out of the game for nearly six months.
The 12-time Grand Slam winner has not played since abandoning his Wimbledon quarter-final against Tomas Berdych in July. Djokovic did not pick up a racket for almost four and a half months after having surgery on his right elbow.
But the 30-year-old Serb will return to action at the Mubadala World Tennis Championship in Abu Dhabi - little more than two weeks before the first Grand Slam of 2018, the Australian Open, gets under way.
"It's been a real roller-coaster ride for me for a year and a half with this issue," Djokovic said in an interview with Sport360 in Abu Dhabi.
"I've never had surgery in my life, I've never had any major injuries that kept me away from the tour for such a long time. Never missed a grand slam in my professional career. It was a big decision, a big call to make."
"I've learned a lesson because I really want to avoid getting to that stage of an injury ever in my career after this.
"I can't wait to get back on the competition level but it was a great experience for me to have.
"And it was a somewhat necessary experience because I got maybe too comfortable with not having major injuries."
Djokovic started hitting balls in Monaco four weeks ago when he began working with Radek Stepanek.
The recently-retired Czech player has joined Andre Agassi to coach Djokovic for the 2018 season.
Djokovic hired Agassi in May to work with him at the grand slams, but has been without a touring coach since splitting from long-time mentor Marian Vajda in the same month.
"I was hitting the ball well from the first practice but the thing is that your muscles, and bone structures and ligaments and joints," said Djokovic, who has slipped down to 12 in the world rankings following his enforced break.
"Everything has to get stronger and fall into place and get used to the stress of hitting the ball and all this stuff.
"I've always had a lot of good times on the court in Abu Dhabi but also off the court I think it's a very pleasant tournament to be part of.
"It allows all of us players to kind of check where we are with our game and in competition play.
"And obviously for me it will be the first match after Wimbledon - and that's why I think I'm probably looking forward to it more than any other player in the tournament."
Three-time Abu Dhabi winner Djokovic joins a six-strong field that also features Dominic Thiem, Kevin Anderson, Pablo Carreno Busta, Roberto Bautista Agut and Andrey Rublev.
Djokovic opens his campaign on Friday against the winner of the match between Bautista Agut and Rublev.
Serena Williams will also make her playing comeback in Abu Dhabi following the birth of her daughter.
Williams, who gave birth to Alexis Jr in September, has not played since winning the Australian Open in January, when she was six weeks pregnant.
It is the first time a women's match has been held at the event, and Williams will play French Open champion Jelena Ostapenko before the men's final takes place on Saturday.