House Speaker John Boehner named three Republicans as potential vice presidential picks for Mitt Romney, but said there is a "long list" of qualified candidates.

The top Republican in Congress said Sen. Marco Rubio of Florida, Sen. Rob Portman of Ohio and Gov. Mitch Daniels of Indiana fit his criteria that the pick be capable of serving as president.

"There are a lot of people that I like. But this is a personal choice for Gov. Romney, and I'm confident that he'll have a running mate that will be helpful to the ticket," Boehner told CNN Chief Political Correspondent Candy Crowley in an interview set to air Sunday.

"I think the number one quality is, are they capable of being president in the case of an emergency?" Boehner added.