By Edward Chaykovsky

British star Amir Khan (31-4, 19 KOs) believes his domestic rival, IBF welterweight champion Kell Brook (36-1, 25 KOs), is worried that a loss to mandatory challenger Errol Spence (21-0, 18 KOs) will kill their potential fight.

Brook has been ordered by the International Boxing Federation to make a mandatory defense against Spence. If he fails to do so, the sanctioning body will strip him of the title.

Khan been advised that Brook has no intention of facing Spence and plans to vacate the IBF title. Brook captured the belt in the fall of 2014, when he traveled to California to win a close twelve round decision over Shawn Porter.

Brook has not fought since suffering a fifth round TKO defeat at the hands of middleweight king Gennady Golovkin in September. In that contest, that saw Brook move up by two weight divisions, he suffered a fractured orbital bone and need surgery.

There are ongoing talks for Khan and Brook to fight each other, but Khan plans to take an interim-fight in April. Khan has been away from the ring since suffering a knockout loss to Saul "Canelo" Alvarez in May. Khan had hand surgery a few months ago, and only recently got back to training.

Brook's promoter wants to stage the Khan-Brook battle in the summer, but Khan says the fight is more likely to take place in the fall.

"We give him a lot of credit for fighting Triple G, but maybe he knew he was going to get beat and nobody would say anything bad about that fight. But now he's fighting someone at his own weight, someone that he knows is going to be a tough fight against, and he just steps down and says 'here take my title, I don't want to fight you.' Because he thinks that a guy beating him at his own weight will kind of kill the fight between me and Kell Brook. He's only going for that money fight," Khan told IFL TV.

Khan has a lot of respect for Spence, who like Khan is a former Olympian. Both Khan and Spence are advised by Al Haymon and fight under the Premier Boxing Champions banner.

"I think Errol Spence is a great fighter. Obviously he's beatable. Obviously every fighter is beatable, but he's a young, hungry fighter who wants to be the best and destined for greatness. He's doing great things in boxing, making a lot of noise. I have a lot of respect for him, I think he's a good fighter," Khan said.