Tierney Sneed contributed reporting.

Senate Republicans girding for an Obamacare repeal vote-a-rama early next week have no idea at this point what they’re going to be voting on — and their leadership’s response has been a collective shrug.

GOP senators emerged from a policy luncheon Thursday saying they had no new information about what Pandora’s box they’ll be opening up if they vote to proceed to debating a base health care bill on the Senate floor next Tuesday.

As they head home for the weekend, senators were similarly unsure when they would find out what their leaders’ game plan will be: a modified version of the current Obamacare repeal and replacement bill that doesn’t have enough votes to pass right now, or revival of the 2015 repeal-and-delay bill that also lacks the support to pass.

The first vote, Senate leaders confirmed to reporters on Thursday, will be to take up the House health care bill, warts and all. After that, GOP leaders are promising a free-for-all of amendments from senators with dramatically disparate versions of how the health care system should be reformed.

Senate Majority Whip John Cornyn (R-TX) couldn’t tell reporters what amendment GOP leaders will throw their weight behind, or when the senators would be informed of the path forward. When asked about senators who want to know what they’re voting on ahead of time, he called that “a luxury we don’t have.”

He assured reporters Thursday that skittish senators will be able to vote on anything they please, “until people get so tired of offering amendments and voting that we finally wrap it up.” If they don’t like what’s left at the end of this vote-a-rama, he promised, “their ultimate protection is to withhold their vote.”

No other senator seemed to have received the memo.

Senate Republican Conference Chairman John Thune (R-SD) hazarded a completely different guess earlier in the day. “I think probably straight repeal,” he said when asked whether the vote would be on the current Senate bill or the repeal-and-delay option.

It isn’t even clear that they have enough votes to overcome the initial procedural hurdle.

Most rank-and-file Republicans told TPM afternoon that they had no idea which model the conference would embrace.

“I’m not sure that’s been clarified yet,” said Sen. Marco Rubio (R-FL). “I’d prefer to know.”

Many senators refused to commit to voting for the vote-a-rama as they rushed to fly home on Thursday, keeping their powder dry until they knew what they were voting on.

“I don’t know what is going to happen next week,” said Sen. Ron Johnson (R-WI), a possible no vote on compromise legislation.

“It’s very nebulous,” Sen. Rand Paul (R-KY) complained, even as he promised to vote to proceed if guaranteed a vote on his amendment for a clean repeal of Obamacare, a major development for the key holdout. “It’s hard to say whether you’ll vote to proceed to something if you don’t know what you’re proceeding to.”

Even senators who promised to back a motion to proceed to debating the legislation expressed exasperation at the process. Particularly, lawmakers vented about the negotiations behind closed doors over big cash handouts targeted at specific state-focused concerns that could buy off individual senators, including the possibility of $200 billion more in assistance to states that expanded Medicaid.

“I’m going to vote to proceed to any vehicle Mitch wants to proceed to, but … it’s starting to feel like a bazaar, $50 billion here, $100 billion there, and I feel like it’s losing coherency so I hope that somehow or another it can move in a different direction,” Sen. Bob Corker (R-TN) told reporters, saying repeal-and-delay would be his preference if the current bill can’t get back on track.

For his part, Senate Majority Leader Mitch McConnell (R-KY) kept his mouth shut throughout the day, grinning at the swarm of reporters packed around Sen. Bill Cassidy (R-LA) as he snuck quickly to the Senate floor before they could turn their attention to him.

Hanging over the almost satirical chaos of chasing senators with no new information to share was the news of Sen. John McCain’s (R-AZ) serious brain cancer. While no one was eager to talk about the legislative effects of the illness, senators admitted the loss of McCain’s vote as he battles the disease could have a major impact on the Senate’s ability to pass anything.

“It always kind of troubles me to think of a terrible diagnosis with regard to [legislative] process,” Cassidy said, before admitting McCain’s situation further endangered the legislation. “That’s the tragedy of the process. Any time you have a vote count that goes one way or the other it effects the policy.”

Adding one more bizarre note to the day: University of Kentucky basketball coach John Calipari, a few years removed from his team’s Final Four victory, milled about outside the Senate lunch after having sat in on a Senate confirmation hearing. As a few reporters wandered over to greet the celebrity others rushed over, worried they were missing some key nugget from a senator they didn’t recognize.

Calipari, who has actively avoided politics ever since a planned fundraiser for Kentucky’s Democratic governor drew flack back at home in 2012, demurred when asked about the GOP’s repeal efforts. But he admitted that getting the team to play as a unit might be harder in the Senate than on the hardwood.

“I’m coaching basketball, which is hard enough. But I’ve got to tell you, governing’s hard,” he told TPM. “That’s part of democracy. You want things to run smoothly but it never does. But it always works out.”