It is always sad when we see one of the sporting greats beginning to succumb to the aging process, struggling to do the things that once made them such a force in their sport. It is even worse when these stars don't know when to call it a day, going on for far longer than they need to.

When it comes to the Serbian tennis star, Novak Djokovic though, things did not quite go like that, since the talented ace was only 23-years-old when he genuinely first thought about actually throwing in the towel on his tennis career.

Novak won his first Grand Slam title at the 2008 Australian Open and he was always there or there abouts in the coming Slams, although he just couldn't seem to put it all together and get his hands on that second big prize he so badly wanted.

In the next few years, the now 31-year-old found himself always near the top end of the world rankings but he could not cope with the fact that he was still losing matches he knew he was capable of winning.

And a surprise defeat at the French Open to Jurgen Melzer back in 2010 was almost the final straw.

"I had this upward kind of spiral and trajectory in my tennis career, in my life, and everything was great," Djokovic said, per the Daily Mail. "And then, all of a sudden, I had this period of two-and-half, three years, where I didn’t win a Slam. I was managing to be three/four in the world, but I just struggled a lot.

"And, for me, being No 3 in the world wasn’t enough. I just was not satisfied with that. And I would always go back, and say, 'Okay, wait, when I was seven, eight years old, my dream and my life goal was always to be No 1 and win Wimbledon. That’s it. And I need to achieve that, no matter what.'

"But then I reached a kind of mentally low point in my career, I think it was after Roland-Garros, one of the four Slams, and I had lost, I was two sets to love up. 

"I lost in five sets in quarter-finals against a guy called Jurgen Melzer, he was in the top 10 in the world, very good player, but I had a match and I just lost.

"I just had a breakdown. I remember going to my parents and talking about this and that, and I just cried, and, 'I don’t know if this is worth it. I don’t know if I should keep going,' and my father was, like, 'Toughen up! Toughen up!' You know?"

It was only after that point, Djokovic got his act together.

Fortunately for Novak, everyone involved in his life and his fanbase all over the world, he did manage to finally get things in order, improve his form and go on to become one of the best, not only of his generation, but possibly ever.

Djokovic has since gone on to win 14 Grand Slam titles, two of those coming in 2018, and he is now only six off of the all-time record of 20, held by Roger Federer.

It is a tall ask to expect him to ever break that record but one thing is for certain, Novak Djokovic has shown that he has the strength, determination, self-belief and talent to have a real good go at it.