When the Houston Rockets and the Minnesota Timberwolves took the court inside the Arena Ciudad de México last November, Dwight Howard, Greg Harden and the rest of the NBA stars were greeted by cheers from the nearly 19,000 fans that showed up for this regular season match-up.

To put this in perspective, the 18,996 Mexican basketball fans inside the arena that night were more than all but nine NBA franchises have averaged this year, and roughly 5,000 more than the Timberwolves draw to their games at the Target Center.

The numbers highlight a largely untapped market for U.S. sports in Latin America – a place with a huge and growing fan base that could bring the type of devotees that teams in the U.S. have been salivating over.

And while the big three leagues—the NFL, NBA and Major League Baseball—all have held exhibition and even regular-season games in the region, critics say that they are not capitalizing as much as they could.

"There are a lot of opportunities to expand into Latin America," Jeffrey Bliss, a professor of sports management at George Washington University, told Fox News Latino. “But most sports – especially baseball – are not taking those opportunities that they should be taking advantage of."

Instead the NFL and NBA have looked much more toward Europe to extend their reach, while MLB has seriously courted Asian markets.

While the American leagues may have the popularity necessary to be successful south of the border, some observers suggest that Latin markets may not have the spending power needed to support a team.

The average ticket price for an NFL game is about $84—which does not include food, drink, parking and other costs involved with attending a game.

"I suspect that the biggest impediments to playing more in Latin America are the difficulty leagues think they will have in getting folks to pay NFL rates for tickets," Ruck said. As well as “fear of crime and the unknown.”

Others argue that the biggest problem may be a lack of investment opportunities for potential team owners.

"The economy has a huge impact," Bliss said. "You need to have other revenue sources because ticket sales won’t cut it. Corporate sponsorships, media rights and merchandise are what really make the money."

With NFL teams kicking off at London’s Wembley Stadium, baseball’s season-opening game taking place at the Tokyo Dome, and Dwight Howard dunking the basketball in Mexico City, it’s clear that athletes in American leagues are more recognizable around the world than they ever have been.

"The NBA strikes me as the sport best positioned to go global as basketball is the second most widely played game in the world," Rob Ruck, professor of sports history at the University of Pittsburgh, told FNL. "But the NFL just might beat them in establishing a division of four teams in Europe."

Sound farfetched? Not according to the head of the NFL’s international division, Mark Waller.

The league made headlines recently by announcing that three regular-season games would be held in the United Kingdom in 2015, and Waller told SkySports that “everything that we've seen from the UK fans is that there is a huge demand for a team and a full season.”

Waller also said he’s “very confident” that 2020 “is probably a realistic timeframe” for establishing a London franchise.

The NFL’s outreach into Latin America, by contrast, has been much quieter.

The league reportedly has been discussing internally the idea of holding the Pro Bowl in Brazil in 2017, a prospect possibly meant to add glamor to an event that has lost much of its prestige in recent decades.

And, surprisingly, only recently did the NFL send representatives to our next-door neighbor, Mexico, to judge the possibility of that country hosting games.

"It’s fair to say that we’ve been encouraged by the growing fan base in Latin America," Waller told FNL. "We’ve been focused on the U.K., which is working very well, and we want take what we learned there and now apply it elsewhere.”

Mexico’s proximity to Texas means the Dallas Cowboys have a large following there, but, believe it or not, the Pittsburgh Steelers are Mexico’s favorite football team.

During the team’s glory years in the 1970s, Mexican TV network Televisa aired Steelers games and helped grow a fan base to the point that, when the Steelers played the Indianapolis Colts in a preseason game in Mexico City in 2000, an estimated 90 percent of the 87,000-some in attendance were Steelers fans.

As recently as two years ago, Ben Blatt at the Harvard Sports Analysis Collective reported that the Steelers have more fans in Mexico alone than the St. Louis Rams and Jacksonville Jaguars do in the entire U.S.

More to the point, the Steelers also have more Mexican followers than there are fans of all NFL teams combined in the U.K.

Even so, the league hasn’t played a regular-season game in Mexico since the Arizona Cardinals and the San Francisco 49ers squared off in 2005. And, as Waller pointed out to Fox News Latino, the impact of traveling to Mexico would be much easier than Europe.

"We have an incredibly strong and vibrant fan base in Mexico," he said. "When it comes to the next phase of development outside the U.S., Mexico is high on our list."

Major League Baseball is another league with a large Latin American fan base – especially in the Caribbean basin – and one with strong ties to the region.

The Dominican Republic is home to academies run by all 30 MLB teams, along with league offices.

More than a fifth (21.5 percent) of all players on 2015 MLB opening day rosters were from Latin America and the Caribbean, and some of the sport's most fervent supporters are from countries like Cuba, Mexico and Venezuela.

But don’t expect the league to expand to Santo Domingo, Havana or Mexico City anytime soon. Despite rumors that the Mexican and Canadian markets would be likely places for expansion, an MLB official told Fox News Latino that a major league club based in Latin America is "not something we’re looking into now."

John Blundell, MLB vice president of communication, did say that the league is looking into playing more regular seasons games in the region and even having an MLB team take the field in Havana for the first time since the Baltimore Orioles played an exhibition game there against the Cuban national squad in 1999.

That same year, baseball held its first international opening day game between the Colorado Rockies and the San Diego Padres in Monterrey, Mexico.

Six times since, MLB has gone overseas to begin the season, but to Latin America only one other time—in 2001, when the Texas Rangers and the Toronto Blue Jays opened in San Juan, Puerto Rico.

Tokyo has hosted opening day four times and Sydney, Australia, once.

"We love expanding the game all over the place," Blundell said. "We get to reach new markets, and the players also love going there."

The NBA is also attempting to expand its reach beyond North America, but competition in European markets from strong local leagues will likely keep the NBA centered in the U.S. and Canada.

Instead, the league has focused on holding exhibition and regular-season games abroad—31 of them in Latin America since 1991, with 21 in Mexico alone.

That strategy, along with the global popularity of the sport and its superstars like Kobe Bryant and LeBron James, has allowed the NBA to become an international brand rivaling that of England’s Premier League.

"The NBA has figured out how to grow the game globally with merchandising and media deals," GWU’s Bliss said. "Other leagues have to figure out how to capture the youth market with a fast-paced, exciting product with star talent."

Recently the NBA and the International Basketball Federation (FIBA) announced that they will host a joint basketball development camp in Havana in late April, with former NBA stars Steve Nash and Dikembe Mutombo and former Portuguese WNBA star, Ticha Penicheiro, participating in a four-day camp with the Cuban men's and women's national squads.

"We've seen the bridges that basketball can build between cultures," NBA deputy commissioner Mark Tatum said in a statement. "We look forward to sharing the values of our game with Cuban youth and learning together through the common language of sports."