Jaalen Best Says Michael B. Jordan Had His Back While Playing Muhammad Ali: 'Like a Big Brother'

Jaalen Best had a heavyweight in his corner while preparing to play Muhammad Ali, and it wasn't another boxer. The 28-year-old star of Prime Video's The Greatest revealed that Michael B. Jordan became a mentor and trusted source of support as he tackled the physically demanding role of the boxing legend.

And considering Jordan spent years taking punches as Adonis Creed, Best couldn't have asked for someone more familiar with the territory.

"Knowing how much I was going to have to give my body, Michael B. was somebody I leaned on a lot," Best told People. "He's like a big brother to me."

Best opened up about their relationship at the show's October 27 New York City premiere, explaining that portraying Ali required serious physical preparation and just as much attention to recovery. The actor regularly visited a masseuse to "help get the kinks out of my body" after training.

"It's something that I needed to rely on throughout that training process," he explained. "It allowed me to show up every single day and give everything."

And Jordan, who executive produces The Greatest through his Outlier Society banner, was there to offer support. "I'm very blessed [to have] Michael B.," Best added. "He's incredible."

Jordan knows the physical demands of boxing training firsthand. He transformed himself into Adonis Creed for three Creed films, eventually making his feature directorial debut with Creed III in 2023.

But Best wasn't simply tasked with recreating Ali's footwork or famous confidence. He had to portray Cassius Clay's evolution into Muhammad Ali, capturing the fighter's life before and after he became a global cultural icon.

And if Best thought the physical training was demanding, getting the role was an entirely different fight. Showrunner Ben Watkins previously revealed that the casting process stretched across 18 months and involved thousands of hopefuls before Best made the final four.

Even then, he still had one last person to impress: Ali's widow, Lonnie. Best traveled to Louisville to meet her, and her response settled the matter. "He's the one in more ways than you know," she told Watkins.

Lonnie later explained that she recognized something deeper than a physical resemblance. "He has a heart like Muhammad," she told People.

That blessing helped put Best at the center of The Greatest, the eight-episode limited series Watkins created and produced with Ali's estate. Omari Hardwick and Dana Gourrier portray Ali's parents, Kai Parham plays his brother Rudy, Giovanni Ribisi stars as trainer Angelo Dundee, Amin Joseph portrays Sonny Liston, and Michael Ealy takes on Malcolm X.

The series follows Ali's rise from an ambitious young fighter to heavyweight champion while exploring the relationships and convictions that shaped his life outside the ring.