Mitt Romney is rumored to be on the verge of endorsing Florida Sen. Marco Rubio for the 2016 Republican presidential nomination.

Reports are the 2012 Republican nominee for president has been eager to lend his support to Rubio. As of early Sunday, details about how he would officially announce his support were still being worked out.

Word is Romney delayed making his position official partly due to his respect for former Florida Gov. Jeb Bush. But after Bush placed fourth in South Carolina and officially suspended his candidacy after yet another poor primary showing, Romney is reportedly ready to move.

Announcement Could Come Before Nevada Primary

Romney spent at least part of the weekend in Utah, and speculation is building he could be ready to formally announce support for Rubio before Tuesday's Nevada Republican caucus, a contest Romney easily won during both his 2008 and 2012 runs at the White House.

Backing from Romney would be Rubio's highest-profile endorsement since he announced his candidacy, and it would offer yet another clear signal that the GOP establishment might be ready to rally around the Florida senator in hopes of slowing down current party front-runner Donald Trump.

Rubio was rumored to have made Romney's short list of 2012 vice presidential candidates and even spent the Fourth of July weekend with him at his New Hampshire vacation home. Romney ultimately chose Paul Ryan as a running mate.

Donald Trump Rolling Along

With Trump having just walked away the winner in the South Carolina primary and reports he leads in 10 of the next 14 states set to go to the polls, the rumored endorsement couldn't come at a much more opportune time for Rubio. 

Nonetheless, Rubio has staunchly denied all reports of Romney being ready to declare him the candidate of his choice. 

"I have no reason to believe he's anywhere near endorsing anyone," he said.

Trump walked away with roughly 33 percent of the vote in South Carolina, while Rubio and Texas Sen. Ted Cruz both managed just 23 percent each.