DUBAI, United Arab Emirates -- It's commonplace for tennis players to have nicknames, and many people refer to Novak Djokovic as "Nole" or "Djoker."
In truth, "Djokovic the Daredevil" would be a more appropriate pet name for the Serbian who has set few limits on what he is willing to try. Apparently none of his endorsement contracts come with clauses that demand he restrict himself to activities that don't threaten life or limb.
He has swam with turtles and dolphins, skied down indoor slopes, taken flight in simulators and danced acrobatically with a "Dancing with the Stars" celebrity and belly dancer and to the pop hit "Gangnam Style" with a court full of ball kids.
This week, while in Dubai to defend his Dubai Duty Free Tennis Championships title, Djokovic, along with his brother Marko and coach Boris Becker, was invited by Dubai's Crown Prince HH Sheikh Hamdan bin Mohammed bin Rashid Al Maktoum to the prince's private indoor wind tunnel for a simulated skydiving experience. The wind tunnel is powered by four massive turbine engines and can reach top speeds close to 200 mph.
And the flying Djokovic claims to suffer from acrophobia.
"I think they say, 'He seems to be of an adventurous spirit,'" said Djokovic when asked why he seems to be the player usually picked to do danger detail. "When they suggested it to me -- well, I'm not very comfortable with heights, in general. So when they said skydiving, but then they said indoors in a tunnel, I said fine."
Djokovic reported that while he wasn't really flinging himself out of a plane in midair, there were pitfalls to his latest exploit.
"It's a lot of fun, and let me tell you, it's not easy," Djokovic said. "If you don't have the right technique, you can hit your head in the mirror and god knows what happens.
"Boris was like a fish out of water," he added, laughing. "He was not very comfortable in there. For some reason he was sinking all the time, going down more than he was staying up, but you can understand that. For us lighter guys, like me and my brother, it was easier to stay up in the air."
As for actually skydiving, Djokovic says "ne", Serbian for "no."
"Jumping from a plane, well, I still have a family to form and I have to save my life -- not risk my life," he said, laughing, to a small group of media last Sunday before the Dubai tournament started. "I'm a little more careful than that."
Whatever Djokovic says, he's obviously the type of person who likes to push himself beyond his comfort zone, a trait that has likely helped him win six Grand Slam titles to date and reach the pinnacle of the ATP world rankings.
Not all of Djokovic's risk-taking, however, happens away from tennis.
This season, Djokovic's tennis-oriented adventure stems from a new alliance with former champion Becker as his head coach. When longtime coach Marian Vajda told Djokovic he' would like to travel less to spend more time with his young family, the search was on for a new addition to the team. After compiling a list of potential candidates, Djokovic and Vajda kept coming back to Becker's name. They were sure he was the man for the assignment.
Djokovic wasn't looking for someone to tinker with or redirect his game, although he admitted that venturing to the net would be a trip he could stand to take more often.
"We are not significantly changing anything in my game," said Djokovic, emphatically. "The biggest part I hope he'll contribute toward is the mental side of my game.
"We have different games. He was a serve-and-volley player, strong and muscular, whereas on the contrary I stay more on the baseline. I still need to learn to use the opportunities that my groundstrokes present to come to the net more."
Where Djokovic is convinced Becker can be instrumental is in teaching how not to throw away opportunities. Not only are there six Grand Slam finals that saw Djokovic's opponent hoist the trophy, but a 2013 French Open semifinal in which he lost 9-7 in the fifth set to his biggest nemesis, Rafael Nadal, still grates on his nerves.
"I've felt I've dropped two or three [Grand Slam] titles that I should have won over the last few years," he said. "That mental edge has been lacking, and hopefully he can contribute."
Having played only two events this season -- the Australian Open, where he reached the quarterfinals before losing to eventual champion Stanislas Wawrinka, and here in Dubai, where he's won the trophy four times -- his feel for how it's going with Becker is limited. For now, he's working hard to keep under wraps whatever he's discovered under Becker's tutelage.
Asked how Becker's coaching style differs from that of Vajda, who has been with Djokovic from the early days, Djokovic chose to paint a picture of harmony among the troops.
"They are getting along really well," Djokovic said. "That means a lot to me, because Marian is more than just a coach to me. He's like a friend, like a brother. We have a very good and friendly relationship. ... And Boris, when he was joining the team, obviously he had some meetings with myself and with the rest of the team, especially with Marian, to try to understand who I am as a person, as a player.
"That's important thing. Whatever he is trying to work on, he discusses with all of us, and we all have a big respect for Boris. I feel like he can contribute in a positive way to my game and to my mental approach on the court."
Yes, but how is Boris different from Marian? How does he give you his message? Persistence was not going to pay off with an answer to the question, but Djokovic was amused his ruse of a long and positive response was seen as not addressing the question posed.
"I can't speak about what we talk about, you know, on the court, but generally it's very positive for the start," Djokovic insisted. "Hopefully, he can bring us a lot of success."
What Djokovic was willing to chat about was the things that have been filling the rest of the time in this new year.
"In the last three weeks after the Australian Open, I've done a lot of things and been to places that I haven't visited since childhood," he said. "I reconnected with a period of growing up and spent time with family. It's something that has given me a lot of food for my soul and a lot of life energy that I can hopefully transfer onto the court."
While it's hard to predict how the intrepid Djokovic will push himself for his next off-court stunt -- some might suggest joining The Flying Wallendas on their high-wire act would be perfect -- we do know he'll be testing himself on the court in each match he plays, with the ultimate goal of adding more Grand Slam titles to his collection.