Jason Moloney is not concerned with a late replacement opponent for his Las Vegas debut late this month.

He was initially set to fight veteran bantamweight Oscar Negrete. During a routine medical check a detached retina was discovered.

Moloney recently discovered that he's facing Leonardo Baez in the ESPN-televised clash on June 25th at the MGM Grand's Conference Center.

"That's boxing," Moloney told AAP. "Expect the unexpected."

Earlier this year, Moloney was scheduled to fight bantamweight Joshua Greer but the fight fell through when the coronavirus pandemic hit - with numerous events falling through or getting postponed.

Baez is taller and has a longer reach, and is dropping down in weight, but Moloney is not worried.

Although he's had to switch up his training camp, as he was preparing for a shorter Negrete and sparring with smaller men. 

"I've had nearly 100 amateur and professional fights in my career and have done a lot of sparring different styles, so I'm confident fighting whoever they put in front of me," Moloney said.

Moloney brings in a record of 20 wins (17 by knockout), and only one loss as a pro. On the other end, Baez has 18 wins (nine by knockout) and two career defeats.

The boxer's manager is also not worried. He feels confident that his fighter is the best boxer in the weight class.

"It's not ideal when you switch a fighter, but it is the nature of the sport," Moloney's manager Tony Tolj said.

"We back Jason's ability against anyone and it's not a matter of if but a matter of when he will fight for a world title."