The quarterback who made a career out of adjusting on the fly is tonight's opening speaker at the convention where "unpredictable" has been the only sure thing so far.

Fran Tarkenton opens Thursday night's run of speakers at the Republican National Convention's closing night. The former Vikings star QB, and Pro Football Hall of Famer, expects to go on stage around 7:15 p.m.

Donald Trump's speech will be the headliner this evening, but Tarkenton plans to kick off what should be another eventful evening with a talk about leadership – he mentioned Bud Grant's influence in a Facebook video posted Wednesday – and the importance of helping small business owners. Tarkenton himself is a small business owner in Georgia, and his Facebook page describes Tarkenton as a "serial entrepreneur."

Tarkenton said he originally declined the invitation to speak, because of "the hate" aimed at Trump. But he changed his mind, Tarkenton said, deciding to engage and help solve America's problems.

Another reason Tarkenton is speaking Thursday: His relationship with the Republican nominee.

"I've known Donald Trump for 48 years," Tarkenton said in his Facebook video. "Not many people out there have known Donald Trump for 48 years. I have. I happen to like Donald Trump. I think he's a terrific leader. What he does is get stuff done. We need somebody inside Washington to get stuff done, and I don't think an insider can do that. I think we gotta go outside to have that happen."

Read more about Trump's big night here, and follow the coverage of the RNC with our Hot Dish Politics blog.