West Bromwich’s Young Mutley has vowed to retire if his all-West Midlands super-fight with Birmingham’s Frankie Gavin ends in a shattering defeat.

Mutley and Gavin are set for a collision course on May 21 on the Frank Warren-promoted Sky Box Office bill at London’s 02 Arena, for the WBO Inter-Continental welterweight title vacated by Kell Brook.

It’s the biggest derby boxing clash since Matthew Macklin beat Wayne Elcock for the British middleweight title in the Birmingham fighters’ ‘Battle of Brum’ in March 2009.

Gavin was set to meet Wolverhampton’s Dean Harrison for the WBO Inter-Continental belt at light welter in December, but pulled out in the week leading up to the fight with flu.

Now Mutley will take on Britain’s only-ever world amateur champion, with today a year to the day since his last fight, a points win over Patrick Bogere.

And the stakes are as high as ever for the 34-year-old, who will call it a day if Gavin hands him a lesson in boxing at the 02.

Mutley – real name Lee Woodley – said: “I depends on how it goes, I will carry on as long as I am winning and looking after myself. The next time I lose, I think that will be it for me.

“I can definitely beat him – I don’t go in there to lose. I have been the underdog in every big fight I have been in and I perform better that way.

“This could get me right back up there, it means a lot to me.”

Mutley started sparring for the fight this week with fellow West Bromwich fighter Marcus Portman, like Gavin a southpaw.

But ring rust is still a concern although, after spending the last four months working full-time as a binman, Mutley is in good physical condition.

The former British welterweight champion has also put himself on a diet and will carry on with his day job, until a short time before the fight.

He said: “I do worry about ring rust, because I don’t box enough. I have been out of the ring for just over a year.

“I am just going to do loads of sparring so, hopefully, I shouldn’t be so bad. I can’t really do anything else.

“That’s always been my downfall – lack of sparring. But I started it on Monday, with Marcus Portman, because he’s a southpaw as well.

“I might have a couple of weeks off work for the fight but, apart from that, I will be working as well as training.

“I go for a run before work at 5am, go to work, then train at the gym in the evenings. I am burning calories all of the time.

“I am also on a diet, every three hours I eat. Porridge when I get up, then egg whites and two pieces of wholemeal bread, jacket potato with beans, tuna and rice, snack at 5pm and my evening meal when I get home, vegetables with fish or chicken.

“My wife Jade does my food for me and, luckily, my seven-month-old son Reon is starting to sleep now.”