ABU DHABI – Daniel Cormier believes Khabib Nurmagomedov will face his toughest test next week against Justin Gaethje at UFC 254.

Cormier, a longtime friend and teammate of Nurmagomedov (28-0 MMA, 12-0 UFC) at American Kickboxing Academy in San Jose, Calif., has been able witness the greatness of the UFC lightweight champion up close over the years. No one has been able to beat “The Eagle,” who has lost just one round in a dozen UFC appearances.

Gaethje (23-2 MMA, 5-2 UFC) is being viewed by many as the biggest threat Nurmagomedov has encountered thus far, and he’ll have the chance to back that up in the Oct. 24 pay-per-view headliner. Cormier has an inherent bias going into the matchup but said he can be neutral enough to realize Gaethje can’t be underestimated.

“I think it’s the toughest fight in the division for (Khabib),” Cormier told reporters, including MMA Junkie, on Tuesday. “I think Justin Gaethje is an absolute stud. They call him ‘The Human Highlight,’ the most exciting guy in the game. It’s true. Not just the most exciting guy in the game but all of combat sports. There is no fighter in the world of sports that is more exciting than Justin Gaethje. Boxing, kickboxing, mixed martial arts – you’ll find nobody more exciting and better. The Justin Gaethje that fought Tony Ferguson in May is more dangerous to Khabib than anyone that he has ever stepped in the octagon with.”

What makes Nurmagomedov so special is his ability to beat anyone and everyone with a nearly identical game plan. His relentless grappling, top pressure and submissions have stifled every foe, but Cormier admits Gaethje’s wrestling and striking is a recipe for disaster.

“With everybody, he tells you (what he’s going to do),” Cormier said. “But you’ve got to be able to stop it. He’s become so good at what he does that you’ve got to be able to stop it. Now, that’s why Justin’s the most dangerous, because Justin has the skill set to stop it.”

Even with that said, Cormier still can’t doubt Nurmagomedov. There have been 28 men who have tried and failed to hand the Dagestani fighter his first career setback, including the likes of Dustin Poirier, Conor McGregor and Edson Barboza.

No one has been able to do it, though, and if Nurmagomedov can top Gaethje at UFC 254, Cormier said he’s not sure anyone will.

“I don’t know if anyone is going to beat him,” Cormier said. “I’m confident in believing that Khabib will retire undefeated. Nobody will beat this guy. He is too committed to who he is supposed to be to get beat by anyone. … I just don’t know if anyone can beat this guy right now. No ’55-pounder should feel that strong when he grabs you.”