Stan Wawrinka's retirement verdict as deep admission made after Djokovic's telling remarks

Stan Wawrinka opened up on his decision to continue playing tennis at the age of 40 after receiving a glowing review from old rival Novak Djokovic. The multi-Grand Slam champions could have faced off at this week's Monte-Carlo Masters. However, Wawrinka lost a tight three-set match to Alejandro Tabilo on Monday, denying himself a duel with Djokovic.

It was a frustrating defeat for the former world No. 3, who admitted opportunities to do well in big tournaments were getting fewer. While Wawrinka is keen to keep competing, the Swiss ace made a deep statement about his future, claiming you could "lose everything" in life.

Another one of Wawrinka's contemporaries, former world No. 7 Richard Gasquet, . After winning his opening match in Monte Carlo on Sunday, Gasquet joked that he would still be able to hit backhands in 10 years' time.

But Wawrinka doesn't feel the same. "I never wondered what I was going to do three years after ending my career, if I was going to continue playing tennis or not. But anyway, with years passing, you play less and less good," he said.

Asked if he could also lose his trademark one-handed backhand, the former No. 3 replied: "In life, you can lose everything."

But he's still enjoying his share of lengthy three-set battles despite being the oldest player in the world's top 100. Last week in Bucharest, the three-time Grand Slam champion won a rollercoaster 6-4 6-7(5) 7-6(1) match before losing in round two.

And Wawrinka found himself embroiled in another tight tussle at the Monte-Carlo Masters. From 3-1 up in the final set, the former champion suddenly lost four games in a row. But he broke to stay alive and drew level at 5-5 before suffering a "frustrating" 1-6 7-5 7-5 defeat to Tabilo.

Afterwards, Wawrinka said: "Frustration increases with years because you know you are getting close to the end and you will have less opportunities of going further in the tournaments if you lose. So it's more frustrating."

But the current world No. 163 is still as passionate as ever about his tennis - and it's the big battles that keep him going.

"[It's] passion of the sport. You know that as an athlete, when you stop there is no comeback possible, especially when you get older. I want to enjoy as much as possible," the Swiss star explained.

"I love playing tennis. Playing tennis, it's a game that I really enjoy. I've had the chance to play all the best tournaments in the world. I want to keep pushing a little bit.

"I enjoy the process. I enjoy the practice. I enjoy playing those big tournaments like here, like today, those big matches, and that's what keeps me going a little bit."

Wawrinka has faced his fair share of injury setbacks throughout his career - having knee surgery and two foot operations - but, for now, he has no major physical challenges.

"For the time being, everything holds up. The whole preparation we are doing tennis-wise and physically is allowing me to be the best I can possibly. Some days are more difficult than others, but overall, I have no problems in the morning," he said.

While Wawrinka is still eager to continue competing, his old rival Djokovic has nothing but respect for the Swiss player's work ethic - and he believes fans have underestimated his career.

"Well, people talk about my age, but what about him? He's 40. He's 40 and he's still going strong," the 24-time Major winner smiled.

"I love Stan. He's a great guy and a phenomenal champion that probably has been underestimated with everything that he has achieved in our sport. Three slams, Davis Cup, Olympic gold. I mean, a legend of the game.

"Truly somebody that is very inspiring on and off the court, and the amount of time that he spends on the practice court is just very admirable for his age that he still keeps going and plays Challenger levels and tries to grind and work his way up and build his game. I give him big credit for that."