America's Caleb Truax has been confirmed as James DeGale's challenger when he makes the fourth defence of his IBF super-middleweight title at London's Copper Box Arena on December 9.
Lee Selby has also been scheduled to defend his IBF featherweight title on the same bill, and will fight Eduardo Ramirez of Mexico.
Next month's fight represents the 31-year-old DeGale's first in the UK in three years and also his first since his bruising draw in January with Badou Jack, since when he has undergone surgery on his right shoulder.
Truax, 34, previously fought for the WBA middleweight title when in 2015 he lost to Daniel Jacobs in his second of three defeats. Last year he also lost to Anthony Dirrell, whose brother Andre was beaten by DeGale the night he won his world title.
"Truax is a good solid fighter with a top pedigree," said DeGale. "He's been in with some quality opponents like Daniel Jacobs, Jermain Taylor and Andre Dirrell.
"I've not boxed in London for a few years so I can't wait to make my return to the ring and soak up the atmosphere from the crowd and put on great show."
Wales' Selby, 30, is already scheduled to defend his title against mandatory challenger Josh Warrington next summer at Leeds' Elland Road, and of the 24-year-old Ramirez, he said: "He is a very good unbeaten fighter and he comes from a good stable.
"There's a lot of pressure on this fight; one loss will mess up my whole career. There's massive fights to be made against Josh Warrington and Carl Frampton next year so it's vital that I come through this fight."