It's hard to know what to think when a physicians practice like Twin Cities Orthopedics buys naming rights from a professional team in the famously violent sport of football.

It's still going to be U.S. Bank's name on the new stadium, of course. What Twin Cities Orthopedics will have its name on is the new Minnesota Vikings headquarters and practice facility in Eagan.

It's just the latest boost to the visibility of TCO, one of the nation's biggest practice groups in orthopedics, the medicine of treating aching bones, joints and muscles.

The news of our National Football League team selling the name to its own headquarters at first was puzzling, a little like hearing that U.S. Bank had decided to collect big fees for renaming its Minneapolis headquarters the Delta Air Lines Center for Operational Excellence.

As it turns out, however, this kind of naming rights deal is more or less typical in the NFL.

There's far more than just advertising to what these sponsors are doing with the teams, but training facility naming deals are still a reminder of just how much big-time professional sports have changed.

They've long stopped being primarily entertainment companies, living off selling tickets to a unique experience. Instead they've turned themselves into media companies, making their money selling advertisers on the chance to expose the eyeballs of their fans to advertising images.

The proxy for figuring out how NFL teams do financially is the Green Bay Packers, who disclose financial information because they are unique among NFL teams in being owned by fans. More than half the Packers' $409 million in revenue last year was from national sources, one way or another almost all derived from advertising. Much of the remaining "local revenue" was also unrelated to ticket sales.

With this new naming deal for the Vikings in Eagan and corporate names all over U.S. Bank Stadium, it's not clear what else is left for the Vikings to sell. The fruits of the Vikings' salesmanship will soon be obvious to football fans when they venture to downtown Minneapolis for a game.

Come game day there will be fans strolling through the Medtronic Plaza, entering U.S. Bank Stadium through the Ecolab Gate and finding their seats after grabbing a beer in the Hyundai Club.

So it's pacemakers and spinal implants, mortgages and checking accounts, whatever it is fans think Ecolab sells and then cars. That's all just to experience the thrill of a live sporting event.

But who is going to complain? Better to have Ecolab and Medtronic footing some of the bill than ask more from the public. And some of us are fans not only of the Vikings but of solid corporate citizens like those two.

Some NFL teams have sold their headquarters' names to companies like carmakers or big banks, but the league also seems to have become popular with health care providers.

In what look to be fairly typical deals, the Washington, D.C., team's new partnership is with a big hospital operator, the Philadelphia Eagles practice at a facility named for a physical therapy provider and the Denver Broncos facility last year was renamed the UCHealth Training Center.

UCHealth, a big nonprofit health system in Colorado, will also begin sponsoring the Broncos' formal injury report, the routinely updated list of Broncos players and their various ailments. Now when the team's fans read about a star player hopefully returning from a sprained knee, it'll be another branding moment for UCHealth.

That seems to be an uncomfortably close link between health care and the terrible things that can happen to players' bodies in football. Last year roughly two dozen NFL players lost their seasons due to knee injuries, primarily injuries to the anterior cruciate ligament, before the regular season even started.

What Twin Cities Orthopedics was looking for in its deal with an NFL team, however, wasn't a closer association with treating football's injuries. One big reason it was done, said CEO Troy Simonson, was to raise awareness of his group's work to improve athletic performance and prevent injuries.

As he put it, "our biggest area of growth is on the sports performance side."

The new location in Eagan, scheduled to open in March 2018, also worked well for TCO's growth plans, with relationships with four high school athletic programs in the area already and the need for a facility in that part of Dakota County to treat its regular patients. One recent project he described in the area was working with a high school's soccer players on strengthening exercises and stretching to prevent knee injuries.

"Everyone wants to perform better," he said. "Obviously, the parts do wear out once in a while," which can lead to an orthopedic procedure.

Twin Cities Orthopedics had done business with the Vikings well before signing this deal and has relationships with other sports teams, too, from clubs and schools to other pros. Among other things, TCO sponsors the breaks in the action when a soccer player gets injured in a Minnesota United FC game.

It was an odd thing to watch last Saturday evening in Blaine, a soccer player writhing on the ground in apparent pain while the public address announcer breezily informed everyone that this moment had been brought to us by Twin Cities Orthopedics.

Maybe this kind of branding opportunity is uniquely suited to soccer, a game played without routine timeouts, the end of a half-inning or other chances to slip in an advertising message. And, of course, an injury break in soccer usually shouldn't cause much anxiety for fans.

If they are genuine fans, they've come to appreciate the highly developed skill in soccer of convincingly pretending to be injured.

lee.schafer@startribune.com • 612-673-4302