This week, 60 Minutes correspondent Jon Wertheim profiled the number one ranked tennis player in the world, Novak Djokovic.

Djokovic won three of the four majors tennis tournaments this year, bringing his total Grand Slam wins to 24 and surpassing the records of Rafael Nadal and Roger Federer, who have won 22 and 20, respectively. Incredibly, Djokovic accomplished this record-breaking feat at 36 years old, an age that he never imagined reaching in the sport.

Wertheim told 60 Minutes Overtime that Djokovic's reign as the most dominant athlete in men's tennis is far from over.

"The guy won three of the four majors, and he came within a couple points of winning all four of them," he explained. "Could he play four more years, five more years? Absolutely."

Wertheim revisited his coverage of Djokovic's rise to the top of men's tennis as a writer for Sports Illustrated, discussed the importance of mental strength in Djokovic's game and looked back at Djokovic's first appearance on 60 Minutes in 2012. 

Djokovic and Wertheim first crossed paths in 2006 at the French Open, when Djokovic was just 19. In a 2007 article for Sports Illustrated called "Not Yet, Novak," Wertheim expressed some skepticism that Djokovic would disrupt the Federer-Nadal rivalry that had existed in men's tennis for so long. 

"There's a sense—even in the locker room—that this is a future champion," he wrote. "But let's hold off before saying he's cracked the Federer-Nadal axis."

"Nobody said, 'Oh, this guy's going to win 24 majors and counting, and reset all the records and surpass Roger Federer and Rafa Nadal who preceded him,'" Wertheim explained. 

That all changed in 2008, when Djokovic won his first Grand Slam tournament, beating Jo-Wilfried Tsonga in the final match to win the Australian Open.

"We all sort of said, 'Ah, maybe this is going to be a three-way race now,'" Wertheim said. 

But cracking that Federer-Nadal axis would take a few more years. Djokovic told Wertheim in his interview that he often felt intimidated when playing against them. 

And then in 2011, Djokovic achieved what Wertheim called one of the "all-time great seasons in tennis history." He won three of the four majors tournaments that year, defeating Federer and Nadal in several high-pressure matches. 

"I think a lot of it was mental and confidence," Wertheim said. "And what he told me was that he was no longer intimidated by those guys."

At the end of that spectacular season, 60 Minutes producer Draggan Mihailovich and 60 Minutes correspondent Bob Simon traveled to Belgrade, Serbia to interview Djokovic, who was then 24. 

Simon asked Djokovic how he felt knowing that this might be the high point of his career. Djokovic confidently replied that he would be in tennis for many years to come. 

"I don't have my limit when I want to say, "Okay, I'm going to play up to that age and then I'll stop," he told Simon. 

Simon asked Djokovic how long the average career of a professional tennis player is. Djokovic guessed that it was "usually around 30 or 32."

"Novak Djokovic did not imagine that at age 36, he would not only still be playing but would be playing at a level commensurate with 2011, and still winning three majors of the four majors, and still finishing the year ranked number one," Wertheim said.

Wertheim asked Djokovic, now 36, who would win in a match against the 24-year-old Djokovic. 

"I think the 36 would win," Djokovic said. "I was slightly faster 10 years ago. But I think I'm probably able to play smarter today. And I'm also able to cope with the pressure moments better than I did ten years ago."

Wertheim said Djokovic's mental strength is a critical factor to his dominance in the sport, and it's something he has developed with age. 

"It's very hard to pull statistics on this, but the guy on the other side of the net sure knows it," he said. "He's the best mental player I think in the history of men's tennis."

Wertheim said "constitution, confidence and self-belief" have given Djokovic an edge in the high-pressure moments of intense matches.

Djokovic said his mental game is not a gift: it's something that has to be worked on over time. Techniques like conscious breathing help him manage stress on the court. He also took up journaling a few years ago. 

"I try to write on paper with a pen as much as I can," Djokovic said. "You're emotionally cleansing...spending some quality time with yourself, with your thoughts. I think it serves you well."

Wertheim asked Djokovic when he thought it would be time to retire. 

"Once the young guys start kicking my butt, then I'll probably, you know, start to rethink and question whether I should keep going," he said. "But for now, it's all good."

The video above was produced and edited by Will Croxton.

In:
• Novak Djokovic
• Tennis