Carl Frampton's fight for the European super-bantamweight title against Kiko Martinez in Belfast on 10 September is off after the Spaniard pulled out.
The champion has withdrawn from the Odyssey Arena showdown because his father is seriously ill.
Belfast fighter Frampton landed the title shot despite having had only 10 professional fights.
Frampton will still fight on the bill but ex-European champion Willie Casey has been ruled out as an opponent.
Limerick man Casey is already down to fight in Belfast a week later when he takes on Daniel Kodjo on the undercard of the Tyson Fury bill at the King's Hall.
Casey relinquished the European belt before losing to Cuba's Guillermo Rigendoux in a WBA title fight in March.
The Limerick fighter is reported to have been contacted by Frampton's camp but the parties were unable to come to an agreement over the 10 September bout.
Martinez's record includes a stunning first-round knockout of Bernard Dunne in August 2007.
The Spaniard is in his third stint as European champion.
Martinez knocked out Bernard Dunne in the first round of a European title fight in August 2007 but then lost the EBU belt when outpointed by Rendall Munroe the following March.
However, he regained the European belt in April when he knocked out Jason Booth in the 10th round in Madrid.
Frampton's bout will be the chief support fight to Paul McCloskey's contest with Breidis Prescott.