Josh Mandel's shocking exit has Republicans concerned. And they don't have much time to replace him.

The latest::Josh Mandel replacements: Mary Taylor out, Butler County Sheriff Rick Jones thinking about it

Minutes after Republican U.S. Senate candidate Josh Mandel quit the race Friday afternoon, reality set in for Republicans. 

Who will run in Mandel's stead? The shocking move leaves Republicans with a month to find a formidable candidate by the Feb. 7 deadline. 

And it has national implications on the GOP efforts to retain control of the Senate, where it maintains a slim 51 to 49 majority.

"I'm concerned," said Hamilton County GOP Chairman Alex Triantafilou. "I think Josh was our best candidate."

Mandel cited the health of his wife, Ilana Shafran, as the reason he will no longer seek the Republican nomination to run against Democratic incumbent Sen. Sherrod Brown.

"Understanding and dealing with this health issue is more important to me than any political campaign," Mandel said. He didn't specifiy the health issue. 

Brown's campaign manager Justin Barasky offered only this response.

"At this time, we wish Josh, Ilana and their family the best of health. We hope for Ilana's full and speedy recovery."

While the campaigns remained reticent, the rest of the political world didn't. 

“Wow,” said Ken Rudin, host of the weekly political radio talk show Ken Rudin's Political Junkie. “This comes as a complete shock to me.”

Who might take his place? 

Mandel's announcement might not be bad news for the Republicans. It might be a chance for a stronger candidate to get in the race.

Rudin and other political experts didn't give Mandel much of a chance against Brown. 

Mandel didn't gain much traction, said Jennifer Duffy, who analyzes Senate races for the nonpartisan Cook Political Report.

"Democrats, whether the state party or Sherrod Brown's campaign, took it to him every single day," Duffy said. "And now that he's out, Republicans might –emphasis on might –be able to recruit a strong candidate who is more of a fresh face statewide."

And we will find out who these fresh faces are in the next few weeks or even days.  

Already in the GOP field is Cleveland banker Mike Gibbons. After the news, he committed to spending an additional $5 million for his campaign.

But he's a first-time politician with little name recognition. 

He said on Friday he's the person to unseat Brown.

"As a conservative outsider, no one is better positioned to end career-politician Sherrod Brown’s career than I am," Gibbons said in a statement. He also offered prayers for Mandel and his family. 

The names of GOP gubernatorial candidates Rep. Jim Renacci and Lt. Gov. Mary Taylor came up frequently. Taylor will not seek the U.S. Senate seat, her campaign spokesman Michael Duchesne told The Enquirer. 

“Mary Taylor is completely committed to running for governor,” her spokesman Michael Duchesne said. “She’s firmly committed to this race.”

Renacci told the Newark Advocate Friday he hadn't thought about it yet. Taylor tweeted her prayers for Mandel's family.

Other names included Cleveland-area U.S. Rep. Dave Joyce and "Hillbilly Elegy" author J.D. Vance. Vance considered a run for Senate last year but ultimately decided against it. 

Kyle Kondik, a political analyst with the University of Viriginia's Center for Politics, said Ohio State Sen. Matt Huffman, R-Lima, is worth mentioning.

“One good thing for Republicans is they have a deep bench in the state, so there are a lot of possibilities there," Kondik said. "But just overall, this is shocking.”

Kasich mum, but friend says he's a 'no'

Don't expect a Senate bid from Ohio Gov. John Kasich, who's term-limited out after this year.

Kasich's political consultant, John Weaver, gave a blunt answer on Twitter. 

"To all the press calling, the answer is no. Bigger fish to fry. #TwoPaths," Weaver wrote, referencing a speech Kasich made during his presidential bid. 

Rudin said Kasich would not be a good fit for Senate as polls show he’s not very popular with the national Republican Party.  And it might serve as a distraction for any 2020 plans Kasich might have to challenge Trump.

But anything is possible.

“The fact that Trump is president was a shock,” Rudin said. “Doug Jones winning in Alabama was a shock. You don’t rule anything out anymore.”

Typically, the president's party suffers congressional losses in the midterm. 

President Donald Trump's national approval rating has foundered below 40 percent since June, according to Gallup polls.

Another factor in Republican's favor– they have far fewer seats to defend in the Senate- eight compared to 26 for the Democrats. 

GOP leadership focused their comments Friday on concern for Mandel and his family.

Ohio Republican Party Chairman Jane Timken praised Mandel's decision but didn't offer specifics on how the GOP will move forward in the race. 

"Josh Mandel has made an honorable decision to be with his family in a time of need," Timken said in the statement. "While we are saddened to see him leave the race, we understand, and offer our thoughts and prayers to his family. Our focus is, and will continue to be, on electing Republicans statewide and continuing to make Ohio stronger."

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Here's Mandel's release: 

Friends & Family,

Over a year ago, I launched a campaign for US Senate to make our state and country a better place for my children and yours. Since then, we’ve built a campaign that has us on a path to defeating Sherrod Brown this November. We’ve led him in every public poll and we’ve been the top fundraising Republican challenger in the country.

That being said, I was raised to believe that family always comes first. I still remember the first two words of advice my father gave me when Ilana and I had our first child: “Be there.” These were the same two words his father told him when I was born.

We recently learned that my wife has a health issue that will require my time, attention and presence. In other words, I need to be there.

Understanding and dealing with this health issue is more important to me than any political campaign. For as long as that takes, whether it is months or years, it is important that I heed my dad’s advice and be there for my wife and our kids.

After recent discussions with our family and healthcare professionals, it has become clear to us that it’s no longer possible for me to be away from home and on the campaign trail for the time needed to run a US Senate race.

Therefore, I’m writing today to let you know that I am ending my campaign for US Senate in order to be there for my wife and our three children. This was a difficult decision for us, but it’s the right one.

While unexpected, I accept that this changeof course is what God has in store for our family at this time. As we read in the Book of Proverbs, “Many are the plans in a person’s heart, but it’s God’s purpose that prevails.”

The issues facing our country are profound and I believe we had a voice and perspective better than the current one in the office. At the same time, I think it’s important to acknowledge the respect I have for Senator Brown for having the passion to advocate for his beliefs and, as Teddy Roosevelt once aptly said, the courage to be “The Man in the Arena.”

I will continue to serve out the remainder of my term as State Treasurer and hope to have the opportunity to serve my state and country again in the future. But in the meantime, I must put my family first. I’m grateful for your understanding.

Josh