Sheffield's Kell Brook has pulled out of his IBF welterweight title defence against Diego Chaves next weekend after suffering a rib injury in sparring, his promoter Eddie Hearn has announced.
Brook was set to make the third defence of his belt against the dangerous Chaves, but having spent time in hospital with the injury and taking the advice of medical experts following scans, the fight has been postponed - and champion will now look to face Chaves later in the year.
The show, at Sheffield Arena, will still go ahead - with the Sky Sports debut of Chris Eubank Jr, against American Tony Jeter.
Doncaster's Gavin McDonnell is also in action as he defends his European bantamweight strap against former world title challenger Jeremy Parodi.
"It's always a bitter blow when an injury causes a fight to be postponed, especially so close to the event," said promoter Hearn.
"Kell picked up a rib injury in sparring yesterday and spent most of the day at hospital yesterday.
"Kell was desperate to fight but it was simply impossible and we will now look to reschedule the bout for the end of the year."
Matchroom Boxing will make a full statement on Monday regarding details of full refunds and partial refunds to those fans still attending the show.