Novak Djokovic names most underrated tennis player ever who is 'very underappreciated'

Novak Djokovic has achieved virtually everything in tennis, lifting 24 Grand Slam titles, claiming an Olympic gold medal, and spending a record 428 weeks at No. 1 in the world. The Serbian superstar had epic rivalries with Roger Federer and Rafael Nadal, facing them on the greatest stages for the biggest titles - but there's one other tennis champion whom he believes is "very underappreciated".

Djokovic had his fair share of heartbreaking defeats throughout his career, including two Grand Slam final losses to one specific player. And the current world No. 5 believes the tennis world often "forgets" about his old foe, Stan Wawrinka.

Aged 40, Wawrinka is still going strong on the tennis tour. A former world No. 3 and three-time Major winner, Djokovic believes the Swiss star doesn't get the recognition he deserves.

Asked who had been the most underrated player he'd faced in his glittering career, the Olympic champion had one clear answer.

"Wawrinka, I think he's very underappreciated and underrated considering he is a three-time Grand Slam champion," Djokovic told the ATP.

"I think people very often forget about him and what he has achieved. He has achieved more than 90-plus per cent of the players ever in the history of the game, so I'd probably pick him."

Wawrinka spent years at the top of the game battling with Djokovic, Federer, Nadal and Andy Murray. He won the 2014 Australian Open, 2015 French Open, and 2016 US Open.

The former world No. 3 also joined forces with countryman Federer to win a gold medal in men's doubles at the Beijing 2008 Olympics, and to claim the Davis Cup trophy for Switzerland in 2014.

Wawrinka may not be at his peak anymore, but the 40-year-old is still grinding it out on the tour and has plenty of passion for tennis. Currently ranked at No. 159 in the world, Wawrinka recently got his fourth ATP Tour-level win of the season in Athens.

He received a wildcard into the main draw and beat Botic van de Zandschulp before losing to world No. 9 Lorenzo Musetti in three sets. Wawrinka was two points away from beating Musetti in a second-set tiebreak.

The world No. 159 recently shared a heartfelt post to social media, explaining why he still played professional tennis.

"I know that as an athlete, people like to think they know when it's time for your to stop. People believe that when you get older, when you don't play at the same level , don't have the same ranking or same result , you should stop," he wrote.

"Passion is not always about the results - it's about pushing your limits. I'm ok not to win a Grand Slam anymore. I'm ok with not being top 10 anymore. But I love the process of always pushing my own limits. I know the end of my career will come one day , but until then , I will always give my best fight."

Wawrinka's words inspired Djokovic, who has also fielded retirement questions in recent years. "Stan Wawrinka also often receives the same question, and I completely agree with him when he says, 'Leave me alone. Let me play, enjoy myself'. I understand people's curiosity about 'when', but for me there is no such countdown in my mind," the world No. 5 told SDNA.