MLS Commissioner Don Garber has made assurances that the competition will expand past 20 teams in the next few years.
With New York City FC set to enter the league in 2015, North America's top flight continues to grow, and MLS will become even more populated down the track with the likes of Orlando City, Miami (led by David Beckham), Atlanta, Sacramento and the Twin Cities all vying for position.
"The league is going to expand. It's not an 'if,' but a 'when,' and it's a 'how many,'" Garber said.
"There's lots of interest among many, many different markets, so we'll get pretty focused on establishing something firmer in the next few months."
He added that the USA was continuing to emerge as a real soccer country: "The overall growth of the sport has been so dramatic over the last number of years by almost any measure.
"Whether it's the league or the national team or the women's game, all the developments are sort of proving the fact that we're a soccer nation."