Amir Khan is worried about his domestic rival and fellow former world champion Kell Brook.

For several years, there was talk of a welterweight showdown between Khan and Brook.

But the fight could never come together for one reason or another.

Last year, the fight appeared to be on the verge of actually happening, when Khan signed a multi-fight deal with Brook's promoter, Eddie Hearn.

But Khan took a pass on fighting Brook and instead did a deal to fight WBO champion Terence Crawford in April.

Brook has been inactive since struggling during a decision win over Michael Zerafa last December.

The fight is still there for the two of them, but Khan believes his rival is a broken fighter and there is too much of injury involved. He wants Brook to retire from the sport before it's too late.

“He should get in line. Kell Brook, I really feel he should retire," Khan told the Ask The Experts podcast, according to The Sun.

“I don’t want to fight him, give him a beating and hurt him. He should retire because he’s had two eye sockets broken, he’s already slurring. He’s been beaten up basically. Kell has nothing exciting going for him, that’s why he keeps calling my name out and living off the back of that.

“It happens in boxing that boxers use other big names to give themselves a big name or keep them relevant. So I just feel that if the fight happens, it happens and he would get hurt. Boxing is a tough sport, especially when someone is already broken. I don’t want to be giving any more punishment to him.

"If he does fight me, there’s only one winner. I know myself, we are different levels apart and I can’t see it happening. The only advice I can give him is to retire."