Sacramento and St. Louis have been invited to submit formal bids for franchises as Major League Soccer's Board of Governors formally unveiled plans Thursday to expand to 30 teams.
Commissioner Don Garber made the announcement at the board's meeting in Los Angeles.
"Professional soccer at all levels is thriving in the United States and Canada and we believe there are many markets that could support a successful MLS club," Garber said in a statement. "Expansion during the last 15 years has been enormously successful and a key driver behind the league's continued rise, and we are pleased that some of the top business and community leaders representing great markets in North America are aggressively pursuing MLS expansion clubs."
The league is currently at 24 teams, with FC Cincinnati joining the league this season. Nashville and Miami are teed up to start next year and Austin will come aboard in 2021.
Phoenix has yet to be awarded an expansion MLS franchise but may still be in the mix. Phoenix Rising FC's ownership group submitted a bid for an expansion MLS team last year, including a potential MLS-sized stadium. The club's ownership met with MLS officials in New York City last summer to discuss a possible expansion team.
Phoenix Rising told ABC15 it is still pursuing an MLS team and is working with the league to ensure all boxes are checked.
Phoenix Rising currently plays in the United Soccer League, the second tier of North American soccer. The club advanced to the USL championship game last year.
The board did not identify markets that would receive teams but groups in Sacramento and St. Louis have been invited to give formal presentations to the league's expansion committee. A decision will be made in the coming months.
Bids are likely to include final stadium plans, commitments of corporate support, composition of ownership groups, details about funding, as well as plans for player development, fan engagement and community programs.
It has not been determined when the new teams will join the league.
MLS has set an expansion fee of $200 million for the league's 28th and 29th teams. A fee has not been set for the 30th franchise.
Sacramento's hopes of landing a team were boosted in January when billionaire Ron Burkle became the new lead investor in the Sacramento Republic soccer team. The team currently plays in the USL. Burkle is a co-owner of the NHL's Pittsburgh Penguins with a net worth estimated at $2 billion by Forbes magazine.
The St. Louis group includes World Wide Technology CEO Jim Kavanaugh and the Taylor family, owners of the rental car company Enterprise Holdings.
