LOS ANGELES - The Philadelphia Phillies, and not the Washington Nationals, have emerged as the clear-cut favorite to sign free-agent outfielder Bryce Harper after meeting with him for five hours Saturday in Las Vegas, three officials told USA TODAY Sports.

The officials spoke on condition of anonymity because of ongoing negotiations, but the Phillies have become the most aggressive team in their pursuit for Harper while the Nationals’ interest appears to be waning. Nationals executives are now calling a reunion with Harper a “long shot.’’

The Phillies, who also have interest in signing free-agent infielder Manny Machado, have yet to make an official offer to Harper, but are confident they will sign at least one of the two free-agent megastars. They were strongly encouraged about their chances of signing Harper after meeting with him, his wife and agent Scott Boras in Harper’s hometown. It was their first face-to-face meeting, which included two slide-show presentations by the Phillies. They are expected to make a formal offer within a week.

The Chicago White Sox and Nationals showed strong interest in Harper early this winter, but the White Sox have yet to make an offer to Harper, and the Nats have not formally engaged with Harper for nearly a month.

Harper turned down a 10-year, $300 million contract proposal that was slightly deferred in September by the Nationals, where he has played his entire career. He met again with owner Ted Lerner on Dec. 22 at his Palm Springs, Calif., home, but there was no inclination that he would take less money or the Nats would raise their offer. Now, that offer might no longer even be available. The Nationals have spent $189 million in free agency this winter, and if they sign Harper, will go over the luxury tax for at least several years.

Nats officials privately say Harper no longer is in their plans, and unless Lerner changes his mind or Harper accepts a contract that pays him less than $25 million a year, they anticipate life without him.

Really, the only $200 million-plus question for the Phillies is whether they sign Harper or Machado. They are prepared to make the largest offer to each of them.

Who knows, maybe even both, with the Phillies refusing to rule out the possibility of having the two 26-year-old superstars on one team.

The White Sox, meanwhile, have focused their attention this past month on Machado, offering him a contract for about $200 million. They also traded for his brother-in-law, Yonder Alonso, and signed his close friend, Jon Jay. Their optimism is also growing, believing that if the Phillies sign Harper, they might be the only true remaining suitor for Machado.

The New York Yankees, who were presumed to be the early favorite for Machado, hosted him last month, but they now have no intention of offering him a mega-contract. They unofficially declared themselves out of the running weeks ago, and on Friday signed infielder D.J. LeMahieu to a two-year, $24 million contract. No other teams have publicly expressed their interest in Machado.

Certainly, there’s no deadline to sign Harper or Machado, but with one month remaining before spring training, the Phillies and White Sox would love to reach deals as soon as possible to maximize their season-ticket sales.

No one knows the outcome for sure, but unless there’s a dramatic twist in these negotiations, their ultimate destinations are becoming clearer.

Harper will be in Philadelphia and Machado will be playing for the White Sox.

Stay tuned.

The suspense is nearing a dramatic conclusion.

Follow Bob Nightengale on Twitter @Bnightengale