World heavyweight champion Anthony Joshua says a fight with fellow Briton Tyson Fury will be his focus if he defeats Andy Ruiz Jr on Saturday.
WBA, WBO and IBF champion Joshua, 29, had hoped to meet WBC champion Deontay Wilder to set up a unification bout, but the American has agreed a rematch with Luis Ortiz.
Joshua told BBC Sport it is time to negotiate a "solid fight".
"I think I can beat Ruiz. If Wilder is not available, I want Fury," he said.
"I said I want to meet Wilder, chat to him and the next day he announces a fight with no date or venue attached to it. I still say there is hope but I think the next person I want then is Fury."
Ruiz, who spoke candidly about struggling with childhood bullying over his body shape, warned that Joshua was "looking past me" before their fight at Madison Square Garden in New York.
Joshua claimed he was just looking at "the bigger picture".
With Joshua, Wilder and Fury all attached to different broadcasters and promoters in the US, negotiations for fights between the three are complex and frustrating.
Former lineal world champion Fury, 30, fights German Tom Schwarz in Las Vegas on June 15.
Asked if he thinks a deal can be done to face Fury, Joshua said: "Probably not.
"These fighters have big egos now and think 'if he wants to fight me he has to come and see me and all that'.
"When I first fought for the title my promoter, Eddie Hearn, said when you get the title you are in a position of power.
"I have done that and I feel there is still a power struggle with people thinking, even though they aren't champion, they still think they are king. Let's put that stuff aside and get a real solid fight under wraps."
Joshua added: "Eddie showed me a video of me yesterday and it made me realise that everything we do in boxing is about memories.
"I want to be able to say I had a great night with Fury, remember fighting Wladimir Klitschko and Alexander Povetkin.
"When all is said and done, all you have left is good memories."
Much has been made of Ruiz's weight in the build-up, and he said victory would prove sweet after being taunted as a child.
"At one point I was a little sensitive about it when I was young," said the 29-year-old, who has born in the US to Mexican parents.
"I was always a big kid. My first amateur fight, I was seven years old and there were no kids at my weight so I fought older guys.
"It took a little bit to get used to and it would get me down at times.
"At one moment I wanted to give up listening to the doubters telling me 'you're too big man, too big to be on the big stage'. So I will be remembering that on Saturday and be like 'I told you so'."
Ruiz added: "As long as you follow your dreams, anything is possible.
"I was a little gangster when I was young. I had my head bald and hung around with the wrong kids.
"Boxing saved my life. There was something about it that made me want to go back and back. I was with the wrong people doing bad things.
"I have been an underdog my whole life. The shape I have, the way I look. I am ready to become Mexico's first heavyweight champion."
Ruiz was reminded of the heavyweight division's greatest upset, when James 'Buster' Douglas shocked Mike Tyson in Tokyo in 1990.
Victory for Ruiz would rank among the most unexpected wins of heavyweight history, and he said Joshua had already turned his focus to the future.
"Right now he is looking past me and he should focus on this fight first," said Ruiz.
"Anything can happen in this game. It takes one punch to change the fight.
"The confidence and motivation is there in me and I just have to execute."
Joshua responded: "People speak about being fully focused on 1 June. I am but you can't not look at the bigger picture.
"I'm sure he is doing it himself. I don't put blinkers on about seeing the future potential.
"I will be confident in my ability and try and get him out of there in good fashion."