Andrew will defend his WBA super flyweight title against Texan challenger Joshua Franco on Tuesday (Wednesday AEST) and Jason, a top-five rated bantamweight, will battle Mexico's Leonardo Baez two days later.

The Moloneys trained under strict protocols in Las Vegas for five weeks and on Saturday night arrived at the MGM, received throat COVID-19 tests and were told to immediately go to their rooms and await the results.

"They said, 'If you get a call in the morning that's not good. If you hear nothing until 8am, then that's great news'," Andrew told AAP on Sunday.

"We didn't get a call so we're COVID free and can leave our rooms and walk around the bubble with our face masks on."

The bubble is a specially created, highly secure area on the MGM grounds designed to stage three weeks of fight cards organised by Top Rank's iconic promoter Bob Arum.

COVID-19 testing for fighters, managers, referees and other support staff continue leading up to the bouts.

The regular testing led to the immediate cancellation of two bouts after boxer Mikaela Mayer and a manager tested positive.

The bubble consists of living quarters, a boxing ring where the ESPN and FOX Sports Australia televised fights take place without a live crowd, training facilities, a dining hall and recreation room.

The tight quarters have already led to some uncomfortable encounters.

"When I opened my door the first person I bumped into was Andrew's opponent Franco," Jason said.

"He didn't want to make eye contact.

"I don't think he knew if I was Andrew or Jason, but he just looked away."

The recreation room has a table tennis table and the Melbourne-born, Kingscliff-based Moloneys plan to have a hit, although they suggested Franco and Baez not ask for a doubles game.

The 29-year-old identical twins are apparently just as lethal at ping-pong as what they are in a boxing ring.

"They would not want to do that, mate," Andrew laughed.

"We're pretty bloody good at table tennis."

Australian Associated Press