Former cruiserweight world champion Tony Bellew has cautioned Francis Ngannou from crossing over to the sport of boxing.

Ngannou, who held the UFC heavyweight title, was stripped of the belt on Saturday night - after failing to reach a new contractual agreement with the UFC.

He was officially released from any contract obligations and is now a free agent, according to UFC president Dana White. The vacant belt will now be up for grabs when Ciryl Gane and Jon Jones collide on March 4 at UFC 285.

Last year, Ngannou was discussing the possibility of facing WBC heavyweight champion Tyson Fury in a boxing match. He was ringside for Fury's knockout win over Dillian Whyte, back in April of 2022 at Wembley Stadium in London.

After that event, Fury and Ngannou discussed the possibility of facing each other in a cross-sport boxing match - similar to the massive showdown between Floyd Mayweather and Conor McGregor in 2017.

“I don’t really care about what [it] would be. I just think it’ll be a fight against Tyson Fury. It can be in a phone booth or wherever [but] that fight will happen, or (even) in the rooftop – that fight will happen. Obviously, he will not compete in MMA. That’s not something that could happen. He would get killed," Ngannou said.

Ngannou has stated in several interviews that he dreams about the possibility of entering the sport of boxing for a high profile fight.

Bellew would rather see Ngannou remain in MMA and stay away from a boxing ring.

“Terrible shame! He will not survive in a boxing ring against anyone of any note. He’s the best MMA heavyweight in the world right now and he needs to stay within his discipline,” Bellew stated.

Ngannou has been on the shelf since dominant win over Gane a year ago. He's been recovering from MCL and ACL injuries.