Frank Warren, promoter for heavyweight contender Daniel Dubois, explains that his boxer's back is fully against the wall in the upcoming fight with Jarrell Miller.

The contest is part of the big 'Day of Reckoning' card on Saturday in Saudi Arabia.

Miller has been a subject of controversy. In 2019, he was scheduled to face Anthony Joshua in a major title fight - but saw himself get pulled from the bout after testing positive for numerous banned substances. A comeback in 2020 was also called off after Miller once again tested positive for a banned substance.

Warren believes Miller has served his time and had no problem in agreeing to match him against Dubois.

"I don't police the sport. That's up to the governing bodies and the various organizations," Warren said to BBC Sport.

"The fact of the matter is he has served his ban and he's free to box. It's a bit like if you go to prison, you serve your time and then the slate is supposed to be wiped clean, and that's how we view it."

Warren indicates that all of the boxers are being tested by the Voluntary Anti-Doping Association [VADA].

Dubois' future as a top contender is certainly on the line. He returns after suffering a knockout loss at the hands of unified champion Oleksandr Usyk back in August.

A loss to Miller would be devastating for him.

"There is so much riding on this for Daniel. This is must-win." Warren says. "He could have won his last fight but something was just lacking at the end and he needs to address that, and this is the fight to do it.

"Whether it's self-belief or what, Daniel has to go out there and impose himself against Jarrell and get himself back to the big table. Otherwise he has a long road back."