• Khabib Nurmagomedov says Cristiano Ronaldo should retire before "younger, hungrier" players "come and take" his place.
• "If you don't leave at the right time, you'll be left behind," the Russian fighter told a reporter, according to translations by RT Sport.
• "It doesn't matter if it's Cristiano or Khabib, people will come and take your place," he added. "My advice to him, and to me as well, is to leave at the right time."
• Ronaldo, 34, has endured his worst start to a domestic season in a decade, scoring nine times as Juventus sits second in Serie A.
• Read more of our soccer coverage here.
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Khabib Nurmagomedov and Cristiano Ronaldo have struck up an unlikely friendship over the past two years.

The pair even go watch each other in action from time to time: Last year, Nurmagomedov visited the Santiago Bernabéu to watch Ronaldo stand out for Real Madrid.

But that relationship may be in jeopardy after the Russian suggested his Portuguese pal should retire before "younger, hungrier" players "come and take" his place.

Nurmagomedov was asked by a reporter on Saturday whether he had "any advice on staying fit" for the 34-year-old soccer star who "seems not to want to retire" just yet, according to translations by RT Sport.

"Well, you know, it's hard to leave something you've done your whole life," he said. "But it doesn't matter whether you want to or not. The time will come when if you don't leave the sport, the sport will leave you."

He added: "If you don't leave at the right time you'll be left behind, as there will be new champions — younger, hungrier, more motivated guys. You won't have the same motivation and hunger you had at the beginning of your career towards the end. You get tired and your body gets old, whether you want it or not. Nobody will be around forever. So it's important to leave at the right time.

"How old is [Ronaldo], 34? At 35 he won't have the same conditioning and reaction time."

Nurmagomedov, 31, also said that it was time he begins to think about retirement himself.

"The Eagle" most recently defeated Dustin Poirier at UFC 242 in September and is next scheduled to take on Tony Ferguson in April as he looks to defend his UFC lightweight championship for the third time.

"It doesn't matter if it's Cristiano or Khabib, people will come and take your place," Nurmagomedov said.

"My advice to him, and to me as well, is to leave at the right time. I haven't taken advice from him about [staying fit] because right now I feel good, and when I start to fall behind in some areas I'll probably consult him.

"But for now he's performing, I'm performing, and we have no problems."

Ronaldo has had a difficult start to the new season with Juventus, scoring just nine goals in Serie A and 11 in all competitions — his worst return at this point in the season in a decade.

Juventus sits second in Serie A and next faces Sampdoria on Wednesday.

• Read more:
• Cristiano Ronaldo is the 25th best player in world football right now, according to a computer algorithm
• Cristiano Ronaldo's agent said the Juventus star is 'the best in history, and you know it' after he placed 3rd in the Ballon d'Or
• Khabib Nurmagomedov says he doesn't like inflicting pain on opponents unless he's fighting Conor McGregor
• Cristiano Ronaldo reportedly makes more money being an influencer on Instagram than he does playing soccer for Juventus

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