(Bloomberg)--Senate Republicans anxiously awaiting a key analysis of their revised health bill have more time to wait, and debate on the controversial measure that had been expected this week will also be delayed following a medical scare involving one of its potential backers.

Two Republicans have come out against the plan, meaning Senate Majority Leader Mitch McConnell must get the rest of his colleagues to vote for the bill. But Senator John McCain will be home in Arizona this week, recovering from unexpected surgery, leaving McConnell at least one vote short of the 50 he would need to advance the measure.

McCain’s surgery to remove a blood clot from above his left eye certainly complicates the timetable, but it also buys McConnell more time to shore up support among a number of holdouts, including Rob Portman of Ohio, Shelley Moore Capito of West Virginia, Lisa Murkowski of Alaska and Dean Heller of Nevada.

The Congressional Budget Office is expected to issue its estimate of the new plan’s impact on health coverage and the federal budget deficit, although not on Monday, as many had anticipated. Regardless of the timing, Republicans hope the report will look better than an earlier version, which said the Republican plan would cause 22 million Americans to lose insurance by 2026.

It’s not guaranteed, though, that the fresh analysis will show dramatically better effects. It’s also not expected to include a full accounting of a new provision, pushed by Republican Senators Ted Cruz of Texas and Mike Lee of Utah, that would allow cheaper health plans free of Obamacare regulations on what elements need to be covered. That assessment could take several weeks, a Senate Republican aide said.

McConnell is struggling to find a path to deliver on seven years of Republican promises to repeal Obamacare. So far, despite strong pressure from President Donald Trump, the middle ground that can win over moderates without alienating conservatives has proven elusive.

The most pressing obstacle Republican leaders face appears to be demands by several moderates to restore funding for Medicaid that would be cut under the Obamacare repeal measure. There is also significant pushback to the Cruz-Lee amendment, which health specialists warn may destabilize insurance markets.

The bill has drawn firm “no” votes from Rand Paul of Kentucky and Susan Collins of Maine, who sit at opposite ends of the ideological spectrum on the bill. Collins said Sunday that “eight to 10” Republican senators have serious concerns. “I don’t know whether it will pass,” she said on CNN.

Moderates who wanted more money for Medicaid and to increase health subsidies for the poor made little gains in the revised bill. Talks are continuing to gain the backing of those lawmakers.

In an interview Friday, Senator Dan Sullivan of Alaska minimized the importance of the CBO score and questioned the assumptions it uses. “Those are not the Ten Commandments coming down from Mount Sinai, that everything in there is gospel,” Sullivan said.

Even so, some of the holdouts, including John Hoeven of North Dakota and Bill Cassidy of Louisiana, said last week that they need to see the CBO report as they weigh whether to support debating the bill in the full Senate.

McConnell’s latest draft bill would add $70 billion more for state stability and innovation funds, leave intact Obamacare tax increases on the wealthy, and put $45 billion toward addressing the opioid epidemic.

McConnell’s initial challenge is to get all the remaining holdouts to agree not to vote with Democrats to block the measure from even reaching the floor for debate.

With their latest version, Republican leaders seemed to shore up support from conservatives, largely by including a version of the Cruz-Lee amendment that would allow insurers to sell skimpier plans and bar people with pre-existing conditions. Still, that language risks being stricken out by a parliamentary challenge under the filibuster-busting procedures McConnell is using.

Lee said last week he’s still reviewing it, but is unhappy that it’s different than what he proposed. If the provision is dropped out altogether, whether by parliamentary challenge or another method, support of both senators and others could drop off.

Meanwhile, Republican governors from states of GOP holdouts have significant sway. Ohio Governor John Kasich on Friday blasted the revised bill as “unacceptable,” which could make it tougher to bring Portman on board.

“Its cuts to Medicaid are too deep and, at the same time, it fails to give states the ability to innovate in order to cope with those reductions,” Kasich said in a statement. “It also doesn’t do enough to stabilize the insurance market, where costs are rising unsustainably and companies are simply dropping coverage.”

Vice President Mike Pence sought to stem such responses Friday, attending the National Governors Association’s summer meeting in Rhode Island to make a pitch for the healthcare bill and lobby governors in private.

During his speech, Pence acknowledged the concerns that both Democratic and Republican governors have raised about the cuts to Medicaid over time and shifting costs to the states. He promised that the measure would restore Medicaid to its original purposes of helping the poor and disabled while giving states the flexibility to administer it properly.

McConnell also has to win over Murkowski, who’s voiced concerns about the plan’s impact on subsidies for consumers on Obamacare’s insurance exchanges, Medicaid cuts, and its one-year ban on funding for Planned Parenthood.

Changes in the revised bill would send hundreds of millions of extra federal dollars to Alaska, which may help persuade her. Alaska is the only state that can benefit from formulas that would steer extra Obamacare exchange market stabilization dollars to high-premium states.