Daniel Dubois has withdrawn from his IBF world heavyweight title defence against Joseph Parker on Saturday after falling ill.

The British boxer was evaluated by a doctor on Thursday, according to a report in the Ring magazine, but is unable to compete. The 27-year-old will be replaced by heavyweight contender Martin Bakole, a dangerous proposition for Parker at short notice.

Related: Joseph Parker: ‘This will mean something different. I’m doing it for myself now’

The bout will be held in Riyadh on the undercard of Artur Beterbiev’s rematch against Dmitry Bivol for the unified light-heavyweight world title.

The champion Dubois was scheduled to be making the second defence of his IBF crown after he stopped Anthony Joshua in five rounds at Wembley Stadium last September. However, the unspecified illness means a chance for Bakole to take on Parker, though the full IBF title will not be on the line.

Dubois has won his 22 professional fights, suffering two defeats along the way. He won the “interim” IBF title against Filip Hrgovic and was promoted to world champion status when Oleksandr Usyk vacated the belt.

New Zealand’s Parker has a record of 35 wins and three defeats. The 33-year-old held the WBO heavyweight title between 2016 and 2018.

The 31-year-old Bakole, who trains in Scotland and is from the Democratic Republic of the Congo, has lost once in 22 fights. Last year he produced the best victory of his career, a fifth-round knockout of the previously unbeaten American prospect Jared Anderson.

The American boxer Claressa Shields, the undisputed world champion in three weight classes, has been suspended and is under investigation after testing positive for marijuana following her victory over Danielle Perkins in Michigan.

The Michigan Unarmed Combat Commission suspended the 29-year-old boxer from competing in the state after an oral fluid sample taken after the heavyweight fight on 2 February showed the presence of marijuana, which is banned in competition by the World Anti-Doping Agency.

"Ms Shields' conduct as a licensed professional boxer constitutes an immediate threat to the integrity of professional boxing, the public interest, and the welfare and safety of professional athletes," the Michigan commission said on Thursday.

The sanctioning body the WBO, which does not have the authority to suspend boxers, has requested a "show notice" from Shields to provide an explanation. The Michigan commission is also conducting its own investigation to determine if disciplinary action is necessary.

Shields is the only boxer to hold every major world title – WBA, WBC, IBF and WBO – in three weight classes and is a two-time Olympic gold medallist. Reuters

“It’s all part of boxing and part of the journey,” Parker told iFL TV. “But one opportunity goes away, and another one comes. I’m fighting Martin Bakole who’s been waiting for a big fight, so let’s get it on. Hopefully we can revisit this [Dubois] fight down the line, I want to be champion of the world.

“Bakole is the most avoided heavyweight, but I love to challenge myself … I’ll have my chance again [for the IBF title] at some point but for now my focus is on Martin Bakole.”

Also on the card in Saudi Arabia, Britain’s undefeated Hamzah Sheeraz challenges Carlos Adames of the Dominican Republic for the WBC middleweight title.