Kell Brook is not interested in fighting Amir Khan in 2015 and will instead pursue a welterweight unification bout with either Floyd Mayweather Jr or Manny Pacquiao.
Brook, 28, will return to the ring for the first time on 28 March, since recovering from his August 2014 stabbing, for a meeting with Jo Jo Dan in Sheffield.
A summer showdown with long-term adversary Khan was discussed in 2014 following his IBF title victory over Shawn Porter.
But Brook has since cooled on the idea of an all-British clash with the Bolton-born fighter and is open to a meeting with the winner of Mayweather v Pacquiao, who collide in Las Vegas on 2 May.
"I think the Amir Khan fight is gone for this year," Brook said. "I am the world champion and I will fight some other massive name. I am not interested in what he [Khan] does next now.
"It makes sense to do a unification fight. No contact has been made yet with either of them [Pacquiao or Mayweather] and I am just focusing on my mandatory challenge at the moment. But I want to be involved in the big fights."
Khan, who beat both Luis Collazo and Devon Alexander in 2014, is yet to secure a fight this year but is open to the challenge recently made by Adrien Broner. The outspoken American claimed his third straight victory since losing his WBA welterweight title in 2013 over John Molina and immediately called out the Brit.
Khan in turn welcomed the challenge on Twitter but has said Broner must first come to the 147Ib welterweight mark before any serious talks can go ahead.
"No one on his [Broner's] team has called me and we've got the same adviser, Al Haymon. The only wait it is going to happen is if he fights me at my weight," he told Fight Hype. "I ain't fighting at 140. He needs to come up to 147 because he ain't getting me to come down."