The highly anticipated Joshua Buatsi-Dan Azeez light heavyweight fight has been postponed on short notice due to a back injury Azeez suffered during his final training session.

Promoter BOXXER announced Tuesday afternoon that their 12-round, 175-pound bout will be rescheduled. The unbeaten Brits were scheduled to square off Saturday night in a main event at O2 Arena in London.

Tickets to Buatsi-Azeez will remain valid for the new date, which hasn’t been announced. Full refunds will be offered to consumers who cannot attend the card on its new date.

“I’m devastated for this to happen [during] fight week,” Azeez said in a statement. “It still hasn’t sunk in. I’ve never had to withdraw from a fight in my career before. I want to apologize to all the fans, especially those travelling to the fight. I am also extremely sorry to my opponent, Joshua Buatsi, to my promoter and to everyone involved who has worked so hard on this date. I hope this fight can be rescheduled as soon as possible.”

Sky Sports was set to televise this 12-round bout between Buatsi (17-0, 13 KOs) and Azeez (20-0, 13 KOs), friends turned rivals from London, in the United Kingdom and Ireland. Peacock, NBC’s streaming service, was also scheduled to stream the event headlined by Buatsi-Azeez as part of BOXXER’s new deal with NBC, which was announced Monday.

“This is a big shock, but everyone at BOXXER is working very hard to ensure we provide clarity for all fighters, teams and most importantly fans as soon as we can,” BOXXER founder and CEO Ben Shalom said in a statement. “I know that Dan would do anything to be in the ring on Saturday night and for this to happen at this stage is devastating. This is a huge fight for British boxing, but the health and safety of our fighters must come first. My heart goes out to Dan and Joshua, who have both completed tough camps, and to the fans, with more than 10,000 having made arrangements to come on Saturday. We will provide an update on the rest of the card and communicate a revised date for Buatsi-Azeez as soon as possible.”

Buatsi, 30, is the number one-ranked contender for unbeaten WBA light heavyweight champ Dmitry Bivol (21-0, 11 KOs). Azeez, 34, is ranked second among the WBA’s 175-pound challengers.

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.