George Groves' first challenger for his WBA world super-middleweight title is Jamie Cox, a dark horse in the World Super Boxing Series.
Groves knows all about Cox, who he used to share a hotel room with when they boxed for the England national amateur team.
But Cox's career has gone under the radar and attracted little interest in recent years after spells of inactivity and trouble outside the ring.
However, Cox (24-0, 13 KOs) -- ranked No. 9 with the WBA -- gets his chance against Groves (26-3, 19 KOs) who became champion with a sixth round stoppage over Russia's Fedor Chudinov in May.
Saturday will be Groves' fifth world title fight while it's the first for Swindon-based southpaw Cox, who can be a spiteful puncher.
But Cox, 31, insists he is ready for the opportunity and the quarterfinal of the eight-man elimination tournament at the SSE Arena, Wembley in London.
"I have done it in the gyms with world champions, now it's time to do it on the big stage," said Cox.
"I am looking forward to showcasing myself and show people what I am about and how hard I work in the gym and the dedication I have to the game."
Cox's professional career has been stop-start and he has yet to fulfil the potential he hinted at as an amateur when he won the ABA Championships in 2005 and was linked to being Amir Khan's final amateur opponent.
After winning light-welterweight gold at the 2006 Commonwealth Games in Melbourne, Cox turned professional with promoter Frank Warren and made his debut in July 2007.
He operated as a welterweight initially, then moved up to super-welterweight in 2011 under new trainer John Costello after 15 months of inactivity. Cox won the Commonwealth super-welterweight title with a unanimous decision over Obodai Sai in November 2011.
But he did not box again until June 2013 and after that was next seen in a ring in February 2015.
Cox's ring absences were down to legal problems as well as a broken hand in 2013. Cox was sentenced to 26 weeks on a common assault charge for allegedly attacking ex-girlfriend Viktoria Gribovskaja at her home in 2015. But Cox's conviction was overturned at an appeal a month later in May 2016. He was also found guilty of assaulting a man outside a Swindon bar in 2010 and received a suspended sentence of six months.
After three fights in 2015, it was nearly a year before Cox made his only appearance in 2016 but has fought three times since May, with his last outing -- a four round points decision -- against journeyman Giorgi Kandelaki taking place in Spain on July 23.
Cox stepped up to super-middleweight in 2015 and overcame Lewis Taylor by a ninth round technical decision on the undercard of Groves' title win at Brammall Lane in May.
Cox is trained by John Costello and in April joined promoter Eddie Hearn's Matchroom Sport.
"We are very close, like family," said Cox.
"John is honest, he has great passion for the game and he has a great eye for boxing. He sees boxing very good and the technical ability, he has a lot of national champions in his gym and that's all down to technique."