Cristiano Ronaldo revealed that he is likely to call a day on his career while at his current club, Saudi Pro League giants Al-Nassr, though he is unsure exactly when that day will come.

The Portuguese forward celebrates his 40th birthday in February and has already surpassed many fans' expectations of how long he would continue playing professional football.

And he has perhaps already hinted at his post-football life, recently starting up a YouTube channel that amassed one million subscribers within 90 minutes - a world record.

And Ronaldo has since claimed that he will "probably" retire while at Al-Nassr and does not see him continuing his playing career at another club.

"I don't know if I will retire soon, in two or three years... but probably I will retire here at Al-Nassr," Ronaldo told Portuguese TV channel NOW. "I'm very happy at this club, I feel good in this country too. I'm happy to play in Saudi Arabia and I want to continue."

And when he hangs up his boots for a final time, it is unlikely that his national team fans will be aware of the moment, having ruled out the possibility of an emotional farewell: "When I leave the national team, I will not tell anyone; it will be a very spontaneous decision on my part."

Ronaldo won't be short of options post-retirement should he wish to remain in football, with many young players likely to be eager to learn from one of the sport's greatest-ever players, but he has played down the prospect of becoming a coach.

"At the moment, I'm not thinking about being a coach of the first team or any team," he added. "It doesn't even cross my mind, I've never thought about it. I don't see my future going through that."

For now, Ronaldo's focus is on helping his country ahead of their upcoming Nations League games under Roberto Martinez: "What I want now is to be able to help the national team."

With the Ronaldo name already one of the biggest brands in the world, showcased by his YouTube following, the striker could pursue a host of avenues as he considers retirement.

And the 39-year-old is open to what lies next, even though the idea of becoming a coach was dismissed: "I see myself doing other things outside of football, but only God knows what the future holds."