Lee Selby will no longer defend his IBF featherweight world title on Saturday after his Argentine opponent Jonathan Barros failed to meet the licensing conditions of the Nevada State Athletic Commission.
Selby, 29, was due to fight Barros in Las Vegas on the undercard of Carl Frampton's WBA featherweight title clash with Leo Santa Cruz on Saturday, but the fight was called off before the weigh-in at the MGM Grand.
The announcement comes a mere 24 hours before Selby's title showdown, with the Welshman having envisioned a unification title shot with the winner from Frampton-Santa Cruz after his bout with Barros.
"I'm terribly sorry and I'm almost in tears, all the hard work I put in with my team, my trainer, my management," said Selby.
"Everything went perfectly but the opponent for some reason can't fight and I am left without a contest. The only good thing is that I am returning home as world champion.
"I'm very appreciative to my fans for travelling over here to watch me fight.
"This was my big stage, my chance to shine. But trust me, I will be back. I will come again. Hopefully I can get straight back in the mix, get a quick win under my belt.
"Then I would like to challenge the winner of Frampton-Santa Cruz."
Selby picked up the IBF featherweight title in 2015, defeating Russian Evgeny Gradovich at the O2 Arena in London by a unanimous technical decision.
The 'Barry Boy Assassin' has successfully defended his belt a further two times, against Mexican Fernando Montiel in October 2015 and the USA's Eric Hunter in April 2016.
Selby has a professional record of 23 victories from 24 bouts including eight by knockout, with his solitary defeat coming back in May 2009 to fellow Brit Samir Mouneimne.