Former European amateur super-heavyweight champion Pulev said the fight would probably take place at the end of the year, instead of 20 June at Tottenham Hotspur’s stadium in London as scheduled.
The 62,000-seat stadium is unlikely to be available after European soccer’s governing body Uefa postponed Euro 2020 to 2021 this week, meaning any rescheduled Premier League fixtures could now run into the summer.
Sharing the full story, not just the headlines
“It is impossible for the fight to take place on 20 June, although I am ready,” Pulev, 38, said.
“The match will take place a few months later, perhaps towards the end of the year.”
Pulev, one of Bulgaria’s most popular sportsmen, challenged for the IBF world heavyweight title in 2014, losing to Wladimir Klitschko in Hamburg via fifth-round knockout.
Joshua last fought in London in September 2018 when he beat Alexander Povetkin at Wembley Stadium.
In his last bout, Joshua out-pointed Andy Ruiz Jr in a rematch to regain the WBA, IBF, WBO and IBO heavyweight titles in December.
In June last year, Ruiz handed Joshua his first defeat as a pro, beating the Briton via TKO in Madison Square Garden in New York.