Fighter retirements frequently come with a grain of salt. Countless boxers and mixed martial artists hang up the gloves, only to be lured back.

Fedor Emelianenko knows that as well as anyone. The legendary former heavyweight champion of storied, defunct Japanese fight titan Pride retired more than a decade ago, taking a 3 ½-year break from competition before a return on the final day of 2015. 

And while Emelianenko (40-6, 31 finishes), still considered by many to be MMA’s all-time greatest heavyweight, found relative success during the past six years with Bellator, he maintains that Saturday’s (9 p.m. ET, CBS) Bellator 290 main event rematch against Ryan Bader is the last bow for “The Last Emperor.”

Why believe him?

“I am 46 years old,” said the famously stoic Russian while speaking through an interpreter via Zoom with The Post this week, punctuating with a laugh and an uncharacteristic grin. 

And he feels like he’s 46, too. When Emelianenko first left his athletic career, he was merely 35. He’d built a three-fight win streak for himself on the heels of three straight losses under the Strikeforce banner. That skid put an end to his remarkable 28-fight unbeaten streak, which included victories over legends such as Antonio Rodrigo Nogueira, Mirko Cro Cop, Mark Coleman and Kevin Randleman.

The final fight of Emelianenko’s career had been in the works for years, complicated first by the global COVID-19 pandemic and, in 2022, by his homeland’s invasion of Ukraine. Bellator president Scott Coker spoke last year of grand plans for a show in Moscow’s Red Square, which fell apart amid global backlash against Russia for its aggression against its geographic neighbor.

Emelianenko, who has held minor political postings in Russia and currently serves as the leader of its amateur MMA union, said he regrets that this sendoff — unlike his first retirement following a win over ex-UFC title challenger Pedro Rizzo in St. Petersburg — could not be on home soil.

“Unfortunately, what happens, happens,” Emelianenko said. “It is what it is. But yes, I do regret it.”

What was within his control, however, was his final opponent. As much as fans on social media expressed hope of the legend facing former champions such as Alistair Overeem, Junior dos Santos or even ex-middleweight king Anderson Silva, Emelianenko dismissed all three as having been cast aside by the UFC while on losing streaks.

Instead, the Russian prioritized Bader, to whom Emelianenko lost four years ago via 35-second TKO in the final of the Bellator Heavyweight World Grand Prix. He still holds the championship belt  — it was vacant at the time — he captured that night. 

“I wasn’t looking into anybody else because my main concern was I wanted to fight the current champion of the heavyweight division,” said Emelianenko, who first captured the Pride heavyweight championship from Nogueira in 2003 and held the belt through the organization’s final event in 2007. “And Bader is the champion of the organization right now, I didn’t want to fight anyone else at this point.”

Bader (30-7, 15 finishes) is a former winner of “The Ultimate Fighter” who rose to prominence in the UFC before becoming Bellator’s light heavyweight champion in 2017. For a time, he held gold at both 205 pounds and heavyweight. Now down to the one crown, he successfully defended his title twice in 2022, earning clear decision victories against Valentin Moldavsky in a unification bout and Cheick Kongo, who is about a year older than Emelianenko.

Win or lose, Emelianenko speaks as if he’s at peace walking out of Kia Forum in Inglewood, Calif., on Saturday night and into retirement. Even the prospect of testing himself against the No. 1 heavyweight in the world, Francis Ngannou, may not be enough to tempt him back for just one more. He’s resigned to Father Time.

“I already decided for myself,” Emelianenko said. “If it’s not Ngannou, it’s going to be something else. … I already decided that I have to leave. I’m no longer the Fedor that I used to be at 26 years old, 31 years old. I’m different right now. This is what I decided, and this is what I want for my life.”

And what might life look like for Emelianenko after Saturday? In many ways, similar to how it has been. He’s still invested in the stable of fighters he trains with and expects to continue accompanying them to fights around the globe — including Anatoly Tokov, who competes right before him at the Forum against middleweight champion Johnny Eblen. Plus, he still heads the amateur MMA union back home.

Oh, and gardening. The MMA great is going back to school to study the industry.

“The industry itself is very interesting. The gardening industry is huge,” Emelianenko says. “It’s a lot of interesting things, and this is why I actually went to university.”