Paul Butler is to fight Puerto Rico’s Emmanuel Rodriguez for the vacant IBF bantamweight title he once held on the undercard of Tony Bellew’s May 5 rematch with David Haye.

The 29-year-old from Cheshire has been rebuilding his career since his only defeat – to Zolani Tete at super-flyweight in 2015 shortly after vacating that title – and can become a world champion for the second time at London’s O2 Arena.

Since that loss he has changed promoters from Frank Warren to Matchroom’s Eddie Hearn, and also switched trainers from Anthony Farnell to first Oliver Harrison and then Joe Gallagher.

“It’s the reason we came over to Eddie in the first place, I knew he would deliver the big fights for me,” Butler said. “I want to win it back then hopefully defend which I didn’t have the chance to do last time.

“It sounded a good idea at the time to vacate but looking back now I should have kept hold of the belt. I should have worked on my strength and conditioning, filled out and defended my title. I’ve definitely got some unfinished business with this.”

He added of the unbeaten Rodriguez: “I never used to look at my opponents, but since I’ve linked up with Joe he’s always sending me little clips.

“It’s a tougher test than the last time I won the title (against Stuart Hall), but I’m up for the challenge. I’ve improved myself.

“He’s touted to be this next big superstar, but how many of them come over here and get turned on their heads?”