During another stop on his “thank you” tour outside Milwaukee on Tuesday night, President-elect Donald Trump talked up Rex Tillerson as his choice for Secretary of State.

"Rex is one of the greatest and most skilled global business leaders of our time,” said Trump to a large crowd.

Tillerson, who lives in Denton County, is CEO of Irving-based Exxon Mobil.

"I went to Russia in late ‘97. Things were bad in Russia. Yeltsin was the president," said Tillerson in April 2015 during an event at Texas Tech University.

Speaking for almost an hour at that appearance, Tillerson shared his experiences around the world, including repairing his company’s relationship with Russia and helping Exxon Mobil invest $10 billion in that country.

In a lighter moment, Tillerson also revealed how he never aspired to be CEO.

"I had achieved all of my career goals in 1994 when I became the division manager of the central production division in Texas. I had about 1,600 people working for me. I had a blast. It just all went downhill from there," he continued with a chuckle.

But the coming weeks could be the toughest of his career as he tries to convince senators he can make deals even as a diplomat.

Senators John McCain and Marco Rubio are among the Republicans who have expressed concern about Tillerson’s 15-year friendship with Russian President Vladimir Putin.

“I think he'll get asked a lot of hard questions. All of these guys are practicing mock confirmation hearings already,” said Doug Deason, a Dallas-based Republican fundraiser.

Several news organizations also report that Trump will choose Rick Perry to lead the Department of Energy.

That’s the federal agency that Perry forgot during his infamous “oops” moment in the 2012 presidential campaign.

Deason said he did not find it ironic that Perry might soon take it over.

“No I think it's awesome because he can go in and wind it down and then make it a former shell of what it was,” explained Deason.

Trump announced Tillerson in a Tweet before dawn on Tuesday morning. The president-elect could release news about Perry at any time.