BLAINE, Minn. - In 85-degree heat, brothers Jake and Jeff Rueter wore black Minnesota United FC scarves and made brats on a hot grill at a pregame tailgating party. That’s when they shared how much they’ve warmed up to the local professional soccer team.

“We will be season-ticket holders for life at this point,” Jeff Rueter said.

The Rueters, of St. Paul, were among a club-record 9,412 fans who traveled Wednesday to the no-frills stadium at the National Sports Center to watch United’s second-division North American Soccer League match against Jacksonville Armada FC. First-time season-ticket holders, the brothers have helped increase the season-ticket base from about 1,600 last season to nearly 4,000 as United plays its fall season.

“Awesome. You wouldn’t think that we’re in Blaine,” said forward Christian Ramirez, one of United’s most-recognizable players.

The record-setting increases in United’s fan base occurred after Major League Soccer in March selected United to become an expansion franchise to begin play in the top U.S. league about 2018.

During MLS’s announcement, a July 1 deadline was set for United to have a plan to fund a $120 million, 18,500-seat stadium in downtown Minneapolis. When that deadline passed without a property and sales tax assistance deal in Minneapolis or at the Capitol, the league and United turned to St. Paul and Mayor Chris Coleman to explore a stadium site in the Midway area near Interstate 94 and Snelling Avenue.

United owner Bill McGuire, MLS Deputy Commissioner Mark Abbott and Coleman plan to meet after the MLS All-Star Game on July 29 to explore possibilities in St. Paul.

United can show the league and St. Paul that they have an increasingly attractive product. United has had more than 9,000 fans per match and has broken attendance records at four of seven matches this year. The team added 500 new seats weeks ago to accommodate growing demand.

United has the third-best average home attendance in the 11-team NASL, behind upstart clubs in Jacksonville, Fla., and Indianapolis, according to NASL figures. But United still has room to grow to meet MLS standards, which had drawn more than 4 million fans across 191 games through Wednesday. At midweek, average attendance is 7,085 in NASL, compared with 20,957 for MLS.

“This is a great live experience and a great atmosphere,” United coach Manny Lagos, a St. Paul native, said at Wednesday’s game. “I don’t think somebody flipped a switch and we had this on.”

Soccer fans can’t attend a United home game without feeling the environment amped up by the team’s Dark Clouds supporters group.

“Minnesota black and blue!” is a routine Dark Clouds chant based on the United Loons’ colors.

The Dark Clouds, who are modeled after countless fan groups for clubs around the world, started 11 years ago when the Minnesota Thunder, a previous iteration to United, played home games in St. Paul in 2004. The idea for the fan-club name came off a joke that you can’t have thunder without dark clouds.

And you can’t have United without Dark Clouds, either. The fan club that started with about a dozen members a decade ago has grown to about 500 this year. The Dark Clouds strive to make the National Sports Center a hostile place for opponents to play.

“It’s the level of involvement with the game,” Dark Clouds member Jim Oliver said. “When you talk to the players about it, they kind of feed off all that singing, yelling and heckling. They really feel that and encourage us to make that kind of noise. You do get to be a part of what is going on in the field.”

Beyond the Dark Clouds, United has two other supporters groups: the newly founded True North Elite, a small rebel-like group that flew pirate flags at the game Wednesday, and MNUFC Loons Nest, another small, more family-friendly group that started last season.