The league on Monday confirmed it is in "advanced discussions" with the ownership of NASL club Minnesota United about becoming an MLS franchise.
Commissioner Don Garber said in a statement that the league is "particularly excited about their plans for a new soccer-specific stadium that will serve as the club's home." The Minnesota United vision includes a stadium to be built in downtown Minneapolis with soccer as the primary tenant.
That aspect of United's plan was the key difference from a competing bid set forth by owners of the NFL's Minnesota Vikings, who hoped to bring an MLS team to their new stadium set to open in 2016.
The Vikings released a statement Monday afternoon, reading: "We have been very excited about the possibility of bringing an MLS team to Minnesota fans and deeply committed to providing a phenomenal stadium experience.
"We offered MLS an ideal situation — a stadium that is certain and will be completed in 2016, a plan that was funded by the public and private sectors to host MLS, and an option that will not require additional government approvals.
"The new multi-purpose stadium also would have accommodated the length of the MLS season and the growth of the sport in this market.
"At the same time, we commend MLS Commissioner Don Garber and Deputy Commissioner Mark Abbott for their continued success in building the MLS brand, and, most importantly, we are pleased to see they believe in the Minneapolis-St. Paul market."
MLS on Monday also said it is open to expanding beyond the previously announced goal of fielding 24 teams by 2020.
The league currently has 20 franchises with the addition of Orlando City and New York City FC for 2015, and will add a team in Atlanta in 2017 and a second franchise in Los Angeles for 2017 or 2018.
Miami also has been promised a franchise if it can sort out a stadium solution, so Minnesota would be the 24th team if everything goes through.
In its statement Monday, though, MLS kept open the possibility that other interested cities — Sacramento, Las Vegas, San Antonio and St. Louis were mentioned — could be considered down the road.
