Major League Soccer executives are coming to Minnesota on Wednesday to make it official — or at least as official as an expansion bid can be without a stadium in place.

But on the very day MLS announced that Commissioner Don Garber was coming to Target Field in Minneapolis for “a major announcement,” the odds of prospective owner Bill McGuire getting significant public help for a new soccer-only stadium dramatically decreased.

Gov. Mark Dayton, reinforcing comments he made last year, strongly signaled that he would close the door on any state financial help for an outdoor soccer stadium that a group led by McGuire, a former UnitedHealth Group executive, wants to build near the Minneapolis Farmers Market.

Dayton said he would likewise oppose any attempt to divert a Hennepin County sales tax, now being used to help pay for the nearby Minnesota Twins’ Target Field, to also pay for a soccer stadium. He called any move to do so a “back-door tax increase.”

The governor led the drive for public money for the new Minnesota Vikings stadium, and the Wilf family, the Vikings’ owners, had been vying with McGuire to get the soccer franchise. The Wilfs would have played indoors at the Vikings’ new $1 billion stadium, but the MLS has expressed a preference for outdoor boutique stadiums like the one championed by McGuire, who also owns the Minnesota United FC soccer club of the North American Soccer League, a level below the MLS.

“I congratulate [McGuire’s group] on an apparent success bringing a team to Minnesota,” the governor said, “and I think if they are doing so, they need to fully realize that this is something they’re going to have to pay for out of their own private resources.”

The governor’s comments seemed to signal that McGuire faces building the stadium, estimated at $150 million, solely with private money or with just minimal public subsidies. McGuire’s partners feature some of Minnesota’s wealthiest citizens, including the Pohlad family, owners of the Minnesota Twins, and Glen Taylor, who owns the Minnesota Timberwolves and the Star Tribune.

The agreement between MLS and McGuire’s group will make the Twin Cities one of 10 metropolitan areas nationally to have five major professional sports franchises — football, basketball, baseball, hockey and now soccer. Of those 10, only Denver’s metro area has a smaller population than the Twin Cities.

Opat backs stadium

Hennepin County Commissioner Mike Opat acknowledged Monday that he has had “preliminary conversations” with McGuire’s group about a stadium. Opat, as county board chairman, was a driving force a decade ago behind a substantial public subsidy for Target Field that included the countywide sales tax.

“The biggest thing right now is for the league to overtly commit to [McGuire’s] group,” said Opat, who is no longer the board chairman. “I think the league needs to commit to them, and then they can start talking about accomplishing a venue of their own. It may have to be entirely [funded] on their own, or with limited public support.”

Opat said he favors “the idea of a soccer venue near the Farmers Market — and enhancing the Farmers Market — but I don’t know if any of my colleagues [on the Hennepin County Board] feel the same way.”

Monday’s news was more evidence that the Wilf family is being passed over by MLS for an expansion franchise. The Vikings have a five-year window to bring an MLS team to their new $1 billion indoor stadium, and were thought at one point to have the inside track to lure a team. The Vikings in December unveiled drawings that showed how the new stadium could be reconfigured for soccer, and some high-profile local soccer enthusiasts began leaning toward the Vikings.

Since the first of the year, though, MLS has been sending increasingly strong signals that it preferred an outdoor, soccer-only stadium, which McGuire has been championing.

McGuire has not detailed how his stadium would be paid for — he has made few public statements in general regarding his plans — and has not ruled out anything, including asking for public subsidies or building it privately.

The question remains of where an MLS franchise would temporarily play its games, should a new stadium be approved and await construction. The team could play temporarily at an expanded National Sports Center in Blaine, home of United FC. Other possibilities include the new St. Paul Saints stadium, Target Field and TCF Bank Stadium.

There were signs again Monday that the Minnesota Sports Facilities Authority, the public agency overseeing the building of the Vikings’ football stadium, was not open to allowing McGuire’s group to play any games in the Vikings stadium. That included having McGuire’s team play in the Vikings’ indoor stadium on a temporary basis or during the coldest parts of the MLS season even after the McGuire group built an outdoor stadium.

Michele Kelm-Helgen, chairwoman of the authority, said the Vikings stadium legislation gave the Wilfs an exclusive five-year window regarding soccer at the stadium that would extend until 2021.

“No other owner of a Major League Soccer team could play there unless the legislation is changed. [We told McGuire] that” previously, she said. “Our attorneys tell us that’s pretty clear.”

John Wendt, a professor of ethics and business law at the University of St. Thomas, said that despite “stadium fatigue” in the Twin Cities, there are ways for McGuire’s group to obtain at least some public funding. “There’s a difference between asking for some public aid versus a billion dollars,” he said. “Some of the [public] financing could be ‘creative’ ”, and McGuire’s group could also pay for the project by selling naming rights.

“The Wilfs, for whatever reason, got so much public blow-back from [getting a large stadium public subsidy], that you know that the next person coming in was going to take some heat,” Wendt said.

Opat meanwhile added that soccer should not be strictly compared to the other major professional sports franchises. “I think soccer is a unique animal,” he said. “My gut tells me there’s a larger cohort of soccer fans out there than all of us think,” and that its fan base is “perhaps not that into the other American professional sports.”

Staff writer Patrick Condon contributed to this report.