Kell Brook has launched a stinging verbal assault on his long-term rival Amir Khan after increased speculation that the British fighter could be the next in line to face Floyd Mayweather.

With Khan no longer scheduled to face Devon Alexander, rumours have increased that he could well challenge Mayweather for his WBC welterweight title in May 2014.

The 26 year old has never fought at the 147lb limit but he has a strong following in America and is seen as a major money spinner for Mayweather who is scheduled to fight twice over the next 12 months.

While Khan could be on the verge of landing a shot at the pound-for-pound number one, Brook will have to defeat Ukrainian Vyacheslav Senchenko in an IBF welterweight title eliminator on Saturday after pulling out of his first world title fight with Alexander through injury.

And Brook is fuming at the thought that Khan could be next in line to face five-weight world champion Mayweather.

"It annoys me when I hear Khan might be fighting Mayweather," Brook told the Daily Star.

"That is because he's not ranked at welterweight, never boxed at welterweight and looked rubbish in his last fight.

"Khan is not what people make him out to be - and people who know boxing will tell you that. It's annoying that he could walk right over me and into a big fight like that because it makes business sense.

"But I've put the hard work in to get into the mandatory position for a shot and I've not been given any shortcuts.

"I've fought all the people I've been supposed to fight to get me a world title fight and it's been hard work. But I really think we've seen the best of Khan. He has peaked and his better years have gone past him."

Brook will hope to get in the title mix with a victory over Senchenko but it will certainly not be easy to beat the man that crushed Ricky Hatton's hopes of a successful comeback when he stopped him in the ninth round just over one year ago.

Should Brook emerge victorious then he will be in line to face Alexander who is next in action against Shawn Porter on 30 November at the Freeman Coliseum in San Antonio, Texas.