On Tuesday, he revealed that his choice is Christian Mitchell.
Mitchell is a former state representative and current first lieutenant in the Illinois Air National Guard who was considered the front-runner for the job.
Mitchell will leave his job as vice president for civic engagement at the University of Chicago, to serve as Pritzker's new running mate.
"There is no one who fights harder for working families than Governor JB Pritzker and I am deeply honored to be his choice for Lieutenant Governor," Mitchell said. "The Governor has led with courage and compassion, and together we've built a foundation that's moving Illinois forward. I'm ready to build on that progress-lowering costs, expanding opportunity, and making sure every community has the resources and opportunities they deserve. This is about delivering real results for the people of Illinois, and I'm excited to get to work."
Mitchell is someone well known to Pritzker, having served for more than four years in his administration as deputy governor. In a one-one-one interview with ABC7 Political Reporter Craig Wall, Mitchell said he is ready to step back into public service in whatever way the governor needs him.
SEE ALSO: Gov. Pritzker announces reelection campaign for 3rd term: 'Keep Illinois moving forward'
"Governor and I stayed friends even the entire time I was in the private sector. We spoke quite a bit. And so, when we first started speaking about this a couple weeks ago, it was a pretty fast process," Mitchell said.
The official announcement that Mitchell was the choice to be the candidate for Illinois' lieutenant governor came in a video Pritzker released on Tuesday morning. But it was recorded the week of June 16, the week before Pritzker formally launched his campaign for a third term.
"Christian Mitchell is a proven leader with deep experience, steady judgment, and an unshakable commitment to the working families of Illinois," Pritzker said. "Whether it's transforming our clean energy future, rebuilding our infrastructure, or keeping our communities safe, Christian has been a force behind so much of our progress. I couldn't ask for a better partner to continue delivering results for the people of Illinois."
When asked why he would want to leave his job with UChicago to be Pritzker's running mate, Mitchell said, "I love the state of Illinois, and I love public services. In my heart, it was really nice to be at the university, and certainly I wasn't looking to leave, but I've dedicated my life to public service."
Pritzker said just Monday that the most important quality of a lieutenant governor is the ability to step into the role of governor if needed.
"I'll certainly be ready to do that. I was fortunate to oversee some of our largest agencies as deputy governor, to pass really big pieces of legislation with the support of our colleagues in the legislature on infrastructure and on clean energy. I'll be ready if necessary," Mitchell said.
On Tuesday, after a downstate bill signing, Pritzker praised Mitchell as someone he has grown to trust.
"He's a guy who knows how to get big things done, and I've worked with him to get it done, and I'm excited for the people of Illinois to get to know him and also for him to become one of their leaders," Pritzker said.
Mitchell credits his mother, a nurse for 38 years, with shaping him into who he is.
He said he got emotional seeing her pictures in the finished video, calling her his hero and favorite person.
"So, she showed me what it looks like to have compassion, what it looks like to work hard, what it means to stand up for what you believe is right, and that if you are not making the world a better place, then you are not paying your rent for living on this earth," Mitchell said.
So, could Mitchell see himself, one day, running for governor?
"I think when you do your job well the future takes care of itself, and right now, I'm running to be lieutenant governor to support Governor Pritzker's agenda, to keep advancing the lives of working families in the middle class and the state of Illinois," Mitchell said.
Mitchell was careful to steer clear of questions about the possibility of Pritzker running for president, saying they will cross that bridge when they come to it.
He said he talked with current Lt. Governor Juliana Stratton on Monday night for some tips about getting back out on the campaign trail.
Pritzker, for his part, said the choice was a tough one, and he looked at other candidates in government and the private sector.