Romney says only he knows who's being vetted after Rubio report

“I get a kick out of some the speculation that goes on,” Romney told Fox News Channel.

“I’m not going to comment on the process of course but I can tell you this, only Beth Myers and I know who is being vetted," Romney adding, referring to the aide he appointed to head his vice presidential search two months ago.

Rubio has long been considered a front-runner for the job, bringing conservative bona fides and high popularity in the crucial swing state of Florida to a potential ticket.

Until recently, indications had been that Rubio was very much in the running. The senator has appeared multiple times on the campaign trail with Romney since the former governor clinched the GOP nomination, earning a warm reception from the assembled crowds. Ties are strong between Romney and Rubio staffers, with many top-level advisers having spent time working for both men. The Florida lawmaker is also slated to appear at a high-dollar fundraiser in New York City with Sen. Kelly Ayotte (R-N.H.) for the super-PAC backing Romney's effort.

It could simply be that the Romney campaign has not asked potential running mates for disclosure documents yet in an effort to keep speculation tamped down. Virginia Gov. Bob McDonnell — another prominent Romney backer from a crucial swing state — said late last month that he also had not yet been asked to turn over any vetting documents. But a report in the Washington Post Tuesday anonymously quoted a Romney aide saying Rubio was not currently among the finalists for the job.

Rubio, asked about the story Tuesday on Fox News, urged restraint in speculation.

"Everyone should just take a deep breath. Gov. Romney's gonna make a great choice," Rubio said, adding he was "not commenting on the VP process."

In his interview with Fox, Romney said his primary concern in choosing a running mate was selecting someone who could "lead the country if that were necessary."

"Fortunately, there are a number of good men and women in my party that would meet that test…But that's the most important element -- would the American people and would I see this person as someone who could lead in that kind of eventuality?” Romney said.

Romney did admit that some candidates were being vetted closely.

“Well, there are a number of people who are being vetted and that's obviously the group that we're considering most seriously.”

But he reiterated only he and Meyers had a good understanding of how things were progressing.

“Even Ann doesn't know.  We talk about the possible people that I might select.  But in terms of who's actually being vetted, that's something only two people know," Romney said.

This story was updated at 4:47 p.m.