Andy Ruiz has shot to the front of the queue to fight Anthony Joshua on June 1.
The Brit is in need of a new opponent after Jarrell Miller failed three drug tests.
And Ruiz will hold talks with Joshua's team today with a view to taking on the heavyweight world champion in New York.
Ruiz is among six names revealed by Eddie Hearn, alongside Luis Ortiz, Michael Hunter, Manuel Charr, Trevor Bryan and Agit Kabayel.
"We will be ready on June 1. I'm coming for those belts. That WBO belt belongs to me. Everyone knows I beat Parker," Ruiz told Boxing Scene .
Joshua's promoters Matchroom will announce Joshua's new opponent for his IBF, WBA and WBO heavyweight title this week.
Anthony Joshua breaks silence on Jarrell Miller's failed drug tests
Miller, meanwhile, has said he "messed up".
In a grovelling video message posted on Instagram , he said it was "time to do right" and pledged to "come back better".
Miller had initially said he had "never knowingly taken any banned substance and when I found out the news I was totally shocked".
"My team and I stand for integrity, decency and honesty and together we will stand to fight this with everything we have," he said.
"This was a voluntarily test that I was very happy to do and these results came just one week after another voluntarily test that I had taken which was completely clean."
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But on Friday he struck a different tone, telling fans: "I messed up. I made a bad call. (There were) a lot of ways to handle the situation, I handled it wrongly and I'm paying a price for it.
"I messed up a big opportunity and I'm hurting on the inside. My heart is bleeding right now - I hurt my family, my friends, my team, my supporters.
"But, I'm owning up to it. I'm going to deal with it. I'm going to correct it. I'm going to come back better and I'm humbled by the experience."
