The date for the game has not yet been announced and will be part of the schedule release in April.
Nearly exactly one year ago, Jeremy Fowler of ESPN.com reported that the Steelers were working on a potential 2018 game in Mexico City at Azteca Stadium.
John Sutcliffe of ESPN Deportes, via USA Today's Cameron DaSilva, reported on January 3 the Rams would give up a home game in Los Angeles to play in Mexico City.
Chiefs owner Clark Hunt is excited to see his team play in its first regular-season game in Mexico. The Rams played in Twickenham, England, in 2016 and 2017. "I dont know how quickly that will happen".
Over the last few seasons, the NFL has made a concerted effort to expand the outreach of the league beyond the United States.
The NFL previously announced three 2018 games in London, between the Seattle Seahawks and Oakland Raiders, Philadelphia Eagles and Jacksonville Jaguars, and Tennessee Titans and Los Angeles Chargers. It's hard to speculate that far out right now but the Steelers will have road games against the Arizona Cardinals, San Francisco 49ers and a yet-to-be-decided AFC West team during the 2019 season. "Mexico has one of the largest NFL fan bases in the world and we are excited to bring Rams football to the millions of fans there". The game is usually good for both offenses, with Mexico City at a higher altitude than Denver, therefore gassing defensive players by the second half. It follows last season's contest between the Oakland Raiders and New England Patriots as well as the Raiders' Monday Night Football clash with the Houston Texans in 2016.
The Rams have been obligated to give one home game to the NFL's International Series because they are playing in a temporary stadium (the Coliseum) until their new home in Inglewood is completed in 2020. Paid attendance for that game was 87,145.