The Mike Zimmer era unofficially begins Friday night when the Vikings trickle out of the tunnel at TCF Bank Stadium. Their preseason opener also kicks off a two-year stint at their new temporary home.

Officials from the Vikings and the University of Minnesota have been preparing for this moment for two years, even before reaching an official agreement last May. For the most part, TCF will look like the facility Gophers fans are used to seeing every Saturday. But the Vikings have taken strides to make the stadium feel like home on Sundays in addition to making $6.6 million worth of upgrades.

“We’ve been in constant contact with both the university and the NFL over the past two years to make this transition as smooth as possible,” said Jeff Anderson, Vikings executive director of communications. “It’s been an incredible effort and extremely collaborative, especially over the last eight months. It’s a strong partnership and we expect that to continue over the next two years.”

The costliest change was the installation of a hydronic heating system under the field and the purchase of a new FieldTurf playing surface, which cost the Vikings approximately $2.5 million. The Vikings — who watched former quarterback Brett Favre suffer a concussion in his final game after a hard tackle to the frozen turf when they were forced to play at TCF in December 2010 — pushed to make that change.

“As an organization, it’s always our focus to keep our player as safe as possible,” Anderson said.

Additional upgrades, not all of which will be noticed by the fans, include increased storage space for team equipment and gameday needs, winterizing the concourse restrooms, installing needed technology for NFL replay reviews, adding heaters to the loge boxes on the fourth floor of the stadium, and putting in 1,720 bleacher seats in the west end zone, bringing the stadium’s capacity to 52,525.