Ryan Burnett will defend his WBA 'super' bantamweight belt against Yonfrez Parejo on the undercard of Anthony Joshua's unification clash with Joseph Parker in Cardiff.
The Belfast man added the WBA title to his IBF belt with a dominant points win over Zhanat Zhakiyanov in October and next faces the WBA's mandatory challenger Parejo on the same bill as Joshua's world heavyweight title fight with Parker on March 31, live on Sky Sports Box Office.
Burnett had to vacate the IBF belt after he was also ordered to fulfil a mandatory defence by that governing body, but the unbeaten 25-year-old is focusing only on producing another impressive performance in front of a huge crowd at the Principality Stadium.
"I'm delighted to be added to this show. It's going to be an incredible experience to defend my world title in front of 80,000 in Cardiff," said Burnett.
"I don't really get involved in the politics, but we knew that when we face Zhakiyanov that it was likely we may have to vacate one of the belts because of mandatory challengers. I've unified the division and now we move on to new challenges.
"I expect a tough fight against Parejo. Our styles should gel for a great fight and I'm looking forward to making another statement on March 31."
Promoter Eddie Hearn had tried to reach an agreement with the IBF's mandatory challenger Emmanuel Rodriguez.
"The IBF called an interim title bout between Emmanuel Rodriguez and Lee Haskins, so we proceeded to make the fight with our WBA mandatory Parejo," said Hearn.
"Last week we were notified that the bout would no longer take place and that Rodriguez's team were not willing to negotiate, and they called immediate purse bids.
"Our deal was already in place with Parejo, so we will vacate our IBF title and continue to face our WBA mandatory."
In the main event, Joshua will put his WBA 'super' and IBF belts at stake against WBO title-holder Parker in a battle of two unbeaten champions.
Alexander Povetkin, a potential future opponent for Joshua, will also appear on the undercard as he battles Britain's David Price.
Watch the Anthony Joshua vs Joseph Parker world heavyweight title unification fight, from Principality Stadium, Cardiff, on March 31, live and exclusive on Sky Sports Box Office.