Undisputed lightweight champion Devin Haney believes UFC star Sean O’Malley would make a big mistake by facing a top boxer in a crossover fight.

In recent months, O'Malley has called for fights with Haney and Gervonta 'Tank' Davis.

In the aftermath of his biggest win, when he captured the UFC bantamweight title from Aljamain Sterling at UFC 292, he called for a fight with Davis.

The crossover boxing scene has exploded in recent years - and this weekend WBC heavyweight champion Tyson Fury will collide with former UFC king Francis Ngannou in a non-title boxing match in Saudi Arabia.

Ngannou is a massive underdog and very few observers are expecting him to last the full distance.

Besides the recent callouts by O'Malley, MMA fighters are consistently challenging boxers for crossover bouts.

“I mean, obviously [I laugh when I hear it], because it’s totally different,” Haney said to The MMA Hour. “Whenever the MMA guys come over to boxing, it’s not good for them, and it’s never going to be good for them. And the same, I don’t disrespect the MMA guys because it’s just a different sport. I know that I can’t compete with those guys in the cage. But when it comes to the boxing ring, they can’t compete with me. So it’s just two totally different styles of fighting.”

If they actually collided in the ring, Haney expect a one-sided demolition if he faced O'Malley.

“It’s not the best thing for Sean O’Malley to get into a boxing ring with me,” Haney said. “It’s just, it’s not. It won’t be competitive. It won’t be competitive. But I respect him in the cage, what he does in the cage. He’s a hell of a fighter in the cage. But when you step into that square circle, the boxing ring, it’s a totally different thing.”