Arthur Abraham will make his Las Vegas debut against the unbeaten Gilberto Ramirez on April 9.
The 35-year-old (44-4-KO29), who edged to a split decision over Martin Murray in Hannover in November, will defend his WBO super-middleweight title at the MGM Grand against the dangerous Mexican youngster (33-0-KO24).
Abraham has not fought in the US since suffering a unanimous points defeat to Andre Ward in California in May 2011, but will return on the undercard of Manny Pacquiao versus Timothy Bradley to end a run of 12 fights on German soil.
"I love to box in my native Germany," said Abraham, "but the offer to compete in Las Vegas, on the biggest stage in the world, was something neither my promoter nor I could possibly refuse."
Promoter Kalle Sauerland told Sky Sports: "Ramirez is undefeated. He's very tall and a bit of a puncher, too.
Arthur feels he has to do these things now to prove a point rather than just sit in Germany, and I can understand that.
"We feel that Ramirez has never been in with anyone on the level of Abraham. It's a big challenge for Arthur, though, to box Ramirez on foreign territory.
"It's a big decision to fight outside Germany but something Arthur wanted to do. He has been to the US, won and lost there but he feels that he has had a second wind in his career. He's The Ring magazine's No 1 in the division.
"Arthur feels he has to do these things now to prove a point rather than just sit in Germany, and I can understand that."
Abraham fought three times in 2015, beating Liverpool's Paul Smith on points for a second time, stopping old rival Robert Stieglitz in six and lastly edging Murray.