• There are 19 teams in the league. Four expansion franchises are in the works, while a fifth, bringing the league to 24 teams by 2020, could wind up in the Twin Cities.

• While the exact expansion fee for a Minnesota team is unknown, a good estimate is around $80 million.

• Average attendance in 2014 is 18,716. That figure is up slightly from last year, while 11 of 19 teams are ahead of last year's attendance pace. That average in the MLS is also higher than the NBA (17,407 average in 2013-14) and NHL (17,718 average in 2013-14).

• 14 of the 19 current teams play in soccer-specific stadiums, but Seattle, which shares a stadium with the NFL's Seahawks, has by far the best average attendance (more than 42,000 per game this season).

• Of those 19 MLS franchises, eight play in markets that also have NBA, NHL, NFL and MLB teams.