DENVER (AP) -- John McCain's potential running mates were in what amounted to a high-stakes waiting game Wednesday as the Republican presidential nominee-in-waiting prepared to announce his running mate in the coming days.

The two believed to be under the most serious consideration, Minnesota Gov. Tim Pawlenty and former Massachusetts Gov. Mitt Romney used humor to dodge repeated questions.

"I'm going to be vice president ... of my fantasy football league," Pawlenty joked at the Minnesota State Fair.

And in Denver, Romney, a Mormon, quipped: "Look, John McCain can take Utah without me."

Two other possibilities said to be longer-shots, former Democrat-turned-independent Joe Lieberman of Connecticut and former Pennsylvania Gov. Tom Ridge, stayed out of sight.

So did McCain.

He spent the past several days in Arizona huddling with advisers and working on his own nomination acceptance speech, as Democrats celebrating the imminent nomination of rival Barack Obama skewered the GOP nominee-in-waiting at the Democratic National Convention in Denver.

McCain aides also are monitoring Gustav, which was a hurricane but weakened to a tropical storm, in the Caribbean. It was threatening to hit the Gulf Coast almost exactly three years after Hurricane Katrina that has become a symbol of government incompetence under President Bush. Should the storm hit the U.S., aides will have to decide whether to rework McCain's upcoming schedule to send him to the region - and whether doing so would be politically smart or not.

A four-term Arizona senator who turns 72 on Friday, McCain is expected to name his vice presidential pick later this week in hopes of curbing any uptick in polling Obama could get following his convention. McCain and his running mate then are expected to appear together at one or more rallies planned for Ohio, Pennsylvania and Missouri in the run-up to the GOP convention that starts Monday in St. Paul, Minn.

For now, at least, the secret is being tightly held.

Speculation is centered on Pawlenty, Romney, Ridge and Lieberman, although it's certainly possible McCain could name any number of dark horse candidates. At one point, GOP officials had been told to prepare for the possibility of an "unconventional" candidate.

"The process in selecting a V.P. is one that John McCain is keeping very close to his chest," Romney said early Wednesday in a round of media interviews in Denver before leaving the Democrat's convention city bound to campaign for McCain at two stops outside Las Vegas. Later, he was heading to his vacation home in La Jolla, Calif., essentially, to wait out the vice presidential sweepstakes alongside some of his most trusted advisers.

"He's a person I have a lot of confidence in, I think he's going to do the right thing," Romney added - though he begged off an invitation to say exactly who that would be. Romney associates say they expect McCain will choose someone else.

For his part, Pawlenty spent part of the day at the Minnesota State Fair, where he, too, shot down questions about his vice presidential chances.

Said Pawlenty: "It's an honor to have your name mentioned, or something like that."

He was scheduled to board a plane bound for Denver late in the evening, and was slated to act as McCain's top surrogate to counter the Democratic convention on Thursday in a round of media appearances.

Lieberman, a close McCain friend whose nomination would rock the GOP, packed his bags Tuesday for a vacation at an undisclosed location outside of Connecticut for an undetermined amount of time.

Pressed if the "vacation" line was just a smokescreen while Lieberman meets with McCain advisers, spokesman Marshall Wittmann said: "To paraphrase Mae West, sometimes a vacation is just a vacation ... He's just on vacation."

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