The boxing match between YouTuber Jake Paul and former world champion Mike Tyson, which was scheduled for July 20th, has been postponed.

The bout, the jewel in the crown of Netflix’s summer line up, at Arlington’s AT&T Stadium in Texas, had been officially sanctioned as a professional fight but Tyson says he has been unable to train, blaming an ulcer flare up.

“Unfortunately, due to my ulcer flare up, I have been advised by my doctor to lighten my training for a few weeks to rest and recover,” said Tyson. “My body is in better overall shape than it has been since the 1990s and I will be back to my full training schedule soon.”

The light-welterweight champion Katie Taylor’s rematch with Amanda Serrano, which was due to take place on the undercard, is also expected to be postponed.

Most Valuable Promotions (MVP), who are staging the event alongside Netflix, said a new date for the fight will be announced on June 7th.