Now the former UnitedHealth Group executive must tackle the hard part — whether to build a $150 million stadium in downtown Minneapolis privately with minimal public involvement or mount an uphill lobbying campaign at the State Capitol for significant public subsidies.

McGuire, whose prospective ownership group includes the Pohlad family, owners of the Minnesota Twins, and Glen Taylor, owner of the Minnesota Timberwolves and the Star Tribune, has received a letter of support from the MLS, according to a person with knowledge of the correspondence. The letter outlines stipulations that McGuire must meet to secure a franchise, including finalizing plans and funding for a proposed outdoor stadium on land just north of the Minnesota Twins' Target Field near 6th Avenue N.

McGuire and a spokesman for Minnesota United FC — the North American Soccer League team McGuire already owns — declined to speak publicly Thursday about the latest developments. MLS spokesman Dan Courtemanche would not confirm a league letter of support for McGuire, saying only that such matters would be "private conversations."

The Vikings also had no comment, but have repeatedly said that Minnesotans would be better off with a MLS team in the new $1 billion indoor NFL stadium that is nearly halfway built.

McGuire, who has largely kept out of the public eye, has been quietly working on stadium plans for several years.

The chairwoman of the Minnesota Sports Facilities Authority said Thursday that McGuire — who has since touted the advantages of outdoor soccer — came to her in July 2013 to see if he could play in the Vikings stadium should he get a MLS team. Michele Kelm-Helgen said she told McGuire that would not be possible because the Vikings had a five-year exclusive window to get a MLS team at the stadium.

"I never heard back from him," she said.

Two months later, in September 2013, attorney Ralph Strangis, representing McGuire, appeared before a business group near Target Field and said that a 15,000- to 25,000-seat soccer stadium could be built nearby for 10 percent of the what the Vikings stadium is costing. The business group unanimously endorsed the stadium plan.

The business group, according to minutes from the meeting, was told that McGuire's "not going to individually fund the development. He wants to get people other than himself involved. This will [also] take some involvement from a government unit."

McGuire since has joined forces with the Pohlads and Taylor.

McGuire in an earlier interview confirmed meeting with Hennepin County Board Member Mike Opat, who helped secure public funding for Target Field. Opat has expressed support for McGuire's plan to build an outdoor stadium near Target Field, and accompanied McGuire's group to New York City for its expansion presentation to the MLS.

Opat has left open the possibility of county financial help, which could include funding nearby roads and other public infrastructure.

MLS timetable

Courtemanche reiterated Thursday that a MLS announcement on adding a 24th team is expected soon. "We remain on track to announce the next MLS expansion market in the next 30-45 days," he said in an e-mail.

But a person with knowledge of the MLS timeline said Thursday that McGuire would not have to have a stadium financing package in place at the time Minnesota was awarded a franchise.

Minnesota is competing with Sacramento for that bid. Miami's bid, which is led by former soccer star David Beckham, still has not secured a stadium, potentially leaving Minnesota, Sacramento and Miami for two remaining franchises.

Minnesota is however considered the front-runner for a franchise, with MLS Commissioner Don Garber saying he wants a Midwestern city to balance the league's geographic makeup, and has praised the Twin Cities' demographics.

Several leading local politicians, including most recently Senate Majority Leader Tom Bakk, DFL-Cook, have been critical of public subsidies for a soccer stadium, but others have tempered their remarks.

Minneapolis City Council President Barb Johnson, a key supporter of the Vikings stadium, said she recently told McGuire's group she was worried a separate soccer venue would drain revenue from the Vikings stadium but added that she would keep an open mind. "They're very hopeful they'll get this franchise," she said.

Others cautioned that McGuire had a long way to go.

"There is a lot less going on than you think — at least with me," Opat said Thursday. "What the league and others are doing, I am not part of any of that."

Staff writer Rochelle Olson contributed to this report.