Republican National Committee Chairman Reince Priebus on Sunday downplayed speculation about a wild-card candidate nabbing the party’s presidential nomination and other controversies related to the July convention now overshadowing the GOP candidates’ campaigns.

The controversies -- particularly about delegates and candidates’ pledges to support the eventual nominee -- have escalated in recent weeks as front-runner Donald Trump continues to struggle to win the 1,237 delegates needed to secure the nomination before the convention.

Meanwhile, rivals Texas Sen. Ted Cruz and Ohio Gov. John Kasich are looking for ways to get more delegates to win the nomination.

Priebus acknowledged on “Fox News Sunday” that delegates won by a candidate in state primaries and caucuses must vote for that candidate in the first round of balloting at the convention, but can later vote for somebody else. However, he called the possibility of another candidate winning in later-round balloting an “extreme hypothetical.”

"You get into a multi-ballot convention whereyou've got five or six or seven rounds, it's possible that a person can be nominated that's not one of the three," said Priebus, who appeared on all of the major Sunday political talk shows. "But I think  ... our nominee is likely to be the one of the three people running."

He also argued that Trump, Cruz and Kasich all suggesting that they would break their pledge to support the eventual nominee is political manipulation or leveraging.

“I really do believe this is positioning,” Priebus told Fox. “I think they want to be loyal to the party. I believe they will be loyal to the party.”

He also said the delegates signed the pledge in exchange for sharing RNC campaign data. However, he dismissed as too preliminary a suggestion about suing a candidate for breaking the pledge.  

Cruz in recent days has tried to make the case that last-running Kasich cannot win the party nomination unless he has top showings in at least eight states. The argument could help Cruz in the upcoming Wisconsin primary and the GOP White House race because it eliminates Kasich as the spoiler.

Trump has 736 pledged delegates, followed by Cruz with 463, then Kasich, who has 143. A total of 1,237 delegates are needed to secure the nomination.

Kasich has won only one contest, his home-state of Ohio, and he has finished in second place or tied for second in five others.

The RNC wrote the so-called 40b rule in 2012 after then-Texas Rep. Ron Paul nearly had enough wins to at least complicate the nomination process for clear front-runner Mitt Romney.

The rule states that at the GOP national convention a presidential candidate must have the support of a majority of delegates from eight different states to win the nomination.

Priebus said Sunday that Romney delegates wrote the rules and that they applied only to that convention. However, he suggested that 40b or some version of it would likely remain, considering this time the rules will be written mostly by Trump and Cruz delegates.