Rep. Tom Emmer, R-Minn., will play Minnesota Gov. Tim Walz in Sen. JD Vance’s final vice presidential debate rehearsals, a source directly involved with the preparations told NBC News.

Those final sessions will cap more than a month of work to ready Vance, an Ohio Republican, for next week’s face-off with Walz in New York.

Former President Donald Trump’s campaign, including key members of Vance’s team, has been honing his debate strategy for more than a month, the source said. The approach has involved in-person and virtual practice sessions over Zoom, as well as “murder boards” — a process intended to work through potentially tough questions.

Jason Miller, a senior Trump campaign adviser, and Vance’s wife, Usha, have been involved in the sessions, the source said, along with Vance’s closest political advisers. Those helping with the prep have immersed themselves in old videos of Walz’s previous debates from his past campaigns in a swing congressional district and from two runs for governor.

The choice of Emmer as a stand-in for Walz provides the Vance team with another Minnesotan and someone who, like Vance and Walz, has deep Midwest roots. Emmer, the House majority whip, has emphasized his past as a youth ice hockey coach. Vice President Kamala Harris’ campaign has been emphasizing Walz’s experience coaching high school football.

“The main focus has been familiarizing [Vance] with Walz’s debate style and policy positions,” said the source involved with the preparations. “The main goal is to destroy Walz’s moderate image.”

The source added that Vance has plenty of experience responding to attacks leveled at him on social media and in other forums.

In his first and, until now, only campaign for office, Vance in 2022 faced then-Rep. Tim Ryan for an open U.S. Senate seat in Ohio. At their final debate, Ryan accused Vance of supporting “great replacement theory,” a conspiracy theory that broadly states that a Jewish-led cabal of liberals is trying to take power by replacing white voters with nonwhite people by any means necessary, including immigration and interracial marriage.

“Here’s exactly what happens when the media and people like Tim Ryan accuse me of engaging in great replacement theory,” Vance responded. “What happens is my own children — my biracial children — get attacked by scumbags online and in person, because you are so desperate for political power that you’ll accuse me, the father of three beautiful biracial babies, of engaging in racism. We are sick of it. You can believe in a border without being a racist.”

Transportation Secretary Pete Buttigieg, the former mayor of South Bend, Indiana, is playing Vance in Walz’s debate prep, a source familiar with those rehearsals said. Walz’s preparations are being led by aides Rob Friedlander and Zayn Siddique. Siddique was also part of the Harris’ debate prep ahead of her recent faceoff with Trump.

Walz’s team also includes includes adviser Liz Allen, Harris-Walz communications director Michael Tyler and Chris Schmitter, Walz’s longtime aide who led his gubernatorial campaigns.

“This debate will serve as another clear opportunity for Governor Walz to present Vice President Harris’ winning vision of a New Way Forward to the American people who are ready to turn the page on Donald Trump,” said Harris-Walz spokesperson Emily Soong.