Kell Brook and Errol Spence Jr will face off on Saturday night at Bramall Lane
Brook has not been in the ring since he was beaten by three-belt middleweight champion Gennady Golovkin in September.
The Brit was a huge underdog to upset the unbeaten Kazakhstani fighter and lost his own perfect record in the bout but gained many plaudits for his performance.
Brook had been in talks with Amir Khan about a potential all-British title fight but when they broke down earlier this year, he agreed to take on his mandatory IBF challenger Spence Jr.
The American is unbeaten in his 21-fight professional career and has been tipped for serious success in the US.
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The pair will clash at Sheffield United’s Bramall Lane Stadium on Saturday night – but when exactly will they take to the ring?
Kell Brook v Errol Spence Jr undercard start time
The coverage of the fight on Sky Sports Box Office gets underway at 6pm with a packed undercard filled with intriguing bouts.
At the top of it, George Groves gets his fourth shot at a world title having twice lost to Carl Froch and once to Badou Jack by a controversial decision.
George Groves was noticabley brief and low-key at his workout
The Brit will take on Fedor Chudinov for the vacant WBA super-middleweight title which he knows could be his last.
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"I know it's a long road back after a loss in a world title fight, I couldn't bear to go through that again," Groves said.
"It's the fourth time and I can't bear to come out without the win.
"I'm a better fighter than I was in those previous attempts, better prepared.
“I think I've learned a lot from them and that will help me on Saturday night."
Kell Brook v Errol Spence Jr fight start time
As with all boxing events, the progress of the undercard will dictate the exact start time of the main event.
However, the ring walks are currently scheduled for 10.30pm meaning the fight should start around 10.45pm but expect that to be a very rough guideline and the bout will likely get underway a bit later.