As the NFL continues to look at expanding outside of the United States, Canada, China, Germany and Mexico have been identified as key markets.

However, those countries still rank behind England on the expansion list. The NFL played three games in London last season and remains confident the city will have a team by 2022. 

In the three London games last season, 40,000 people bought tickets to the entire series. That group, the league believes, could make up the initial fan base for the first European team.

Now, the league will continue to explore other markets.

"The work we're doing now is to ask, 'How do we accelerate the agenda in Mexico, Canada and China?'" Mark Waller, NFL EVP, International told NFL.com.

"Those would be our next stage, and we have offices in those three countries. And then, after those, where should be our focus? I think we've concluded that Brazil and Germany are the next two frontier markets, which is where the Pro Bowl idea comes from."

The NFL has floated the idea of playing the Pro Bowl in Brazil in 2017 to explore the league's potential South America.

As for Germany, the country that once housed five of the NFL Europe teams, the league has eyed Frankfurt and Dusseldorf as the most likely spots to play an International game. Though, Berlin and Munich remain a possibility. 

The NFL hopes to expand International Series to include Mexico and Germany in 2017.