Donald Trump’s party in Cleveland this week is about to kick into high gear -- but unless the Republican presidential nominee can bridge the rift with Ohio Gov. John Kasich, Trump's chances of carrying the key battleground state will remain in doubt.

There are signs, however, that some top Ohio Republicans are parting with Trump's former rival in his refusal to help elect the billionaire businessman, realizing their support may be key in a contest that polls indicate will be tight. 

“I think the state delegation is coming together, and the more and more I’m with them, I realize that,” Rep. Jim Renacci, R-Ohio, told FoxNews.com Wednesday in Cleveland. “If the election were held today, Trump would win.” 

He seemed to nudge Kasich, saying, “This is a team sport. The team has to come together.”

The display on the convention floor Tuesday night was striking, however, as just about every state delegation cast its votes for Trump save for the convention host state of Ohio, which awarded its delegates to Gov. Kasich based on the state’s primary results.

Kasich, meanwhile, has complicated the unity push by refusing to endorse Trump and not attending the convention, after a hard-fought GOP presidential primary in which Trump prevailed over 16 major challengers including Kasich, whose only win was his home state Ohio.

Though not officially involved in the four-day convention, Kasich has worked the fringes all week -- giving speeches that include thinly veiled criticisms of Trump.  

“I’m thrilled to be in Cleveland, but it’s not where I need to go because [the platform] is not what I stood for throughout the campaign,” Kasich said at a speech before the U.S. Hispanic Chamber of Commerce. 

Kasich is particularly at odds with Trump’s positions on immigration, which includes plans to build a wall along the southern U.S. border to keep out illegal Mexican immigrants and his calls to temporarily ban Muslims from entering the country, amid a series of global terror attacks by radical Islamic terrorists. “This anti-immigration is unhealthy,” Kasich said later Tuesday, in a speech before the International Republican Institute.

Still, some other top Ohio Republicans are nudging their colleagues toward unity.

Dave Yost, Ohio auditor of state, published an op-ed on Cleveland.com Wednesday arguing that despite Trump’s “flaws” he’d bring a better team to Washington than Hillary Clinton.

“Ultimately, that will be what this election is about. It's not the coach, it's the team,” he wrote.

Ohio voters picked President Obama in the past two presidential elections, after going for Republican President George W. Bush in the two previous White House races.

Trump does have the support of Ohio Sen. Rob Portman, though the senator is in a tough reelection bid, with Washington Democrats making him a top target for defeat.

Portman told FoxNews.com on Wednesday that the state delegation seems to be coming around to the idea of backing Trump.

“I was talking to people this morning, and everybody was in a good mood talking about it,” he said.

The Trump-Kasich tensions flared again Wednesday, though, after a report that Trump’s camp dangled the VP slot to Kasich. Trump later tweeted that Kasich “was never asked by me to be V.P.”

Trump campaign manager Paul Manafort recently called Kasich “petulant” for avoiding the convention and not endorsing Trump, despite taking a pledge to do so.

The remarks brought a sharp response from Ohio Republican Party Chairman Matt Borges that also suggested the Trump campaign has misplayed its effort to win over the state GOP delegation.

He posted on Twitter that Manafort “still has a lot to learn about Ohio politics. Doesn't know what he's talking about. Hope he can do better.''

Republicans from outside Ohio say it’s time to unite.

David Avella, chairman of Republican recruiter GOPAC, said Wednesday it will be important for the Trump campaign and top Ohio Republicans to come together, for the good of the entire Republican ticket from presidential to congressional candidates.

“Trump needs and wants every Republican he can get. He needs to be above 90 percent of Republicans to get the votes he needs. … A lot of that is going to be the result of the party coming together after this convention,” Avella told FoxNews.com. “As far as Governor Kasich, he has a right to support whoever he wants, but this is a binary choice and if you’re not for Donald Trump, you’re for Hillary Clinton.”

At the same time, he said this election has shown “voters don’t care who the politicians are supporting,” and time will tell what the impact of lackluster support from Ohio officials may be. 

In a state like Ohio, small shifts in support could make the difference. One recent Quinnipiac University poll showed Clinton and Trump tied at 41-41 percent in the state. 

Former Arkansas GOP Gov. Mike Huckabee acknowledged Wednesday that the Republican path to the White House indeed goes through Ohio. But he argued this year’s unconventional race suggests history might not have to repeat itself for a GOP win.

“Everything this year has been turned on its head,” said Huckabee, while calling Kasich’s actions this week “very embarrassing.”

“He could have at least shown up and said hello,” he said, arguing the governor at least owes a personal thanks to the police officers who have come from across the country to protect convention-goers in his state.

FoxNews.com’s Judson Berger and Fox News’ Chad Pergram contributed to this report.