FILE - In this Aug. 13, 2016, file photo, the Los Angeles Rams take the field at Los Angeles Memorial Coliseum for a preseason NFL football game against the Dallas Cowboys, in Los Angeles. Opened in 1923, the Coliseum first gained the Rams as a tenant in 1946 when they moved west from Cleveland. (AP Photo/Ryan Kang, File)

FILE - In this Jan. 3, 2016, file photo, the Dallas Cowboys jog onto the field at the start of an NFL football game against the Washington Redskins at AT&T Stadium in Arlington, Texas. The first stadium with construction costs that passed the $1 billion price tag, AT&T Stadium opened for the Cowboys for the 2009 season in the suburb of Arlington with a massive, center-hung, high-definition videoboard as the premier attraction among many Texas-sized amenities.(AP Photo/Roger Steinman, File)

FILE - In this Feb. 1, 2013, file photo, the Superdome, where the NFL Super Bowl XLVII football game between the San Francisco 49ers and Baltimore Ravens will be played on Feb. 3, is seen at sunset in New Orleans. The Superdome has outlasted seven other domed stadiums from the AstroTurf era that have come and gone, even surviving Hurricane Katrina that forced the Saints to play elsewhere in 2005. The spaceship-like building, which opened in 1975, has hosted seven Super Bowls. (AP Photo/Charlie Riedel, File)

FILE - In this Sept. 24, 2017, file photo, Lambeau Field is seen during the first half of an NFL football game between the Green Bay Packers and the Cincinnati Bengals, in Green Bay, Wis. Opened in 1957 and eventually named for the famed franchise’s first head coach, Lambeau Field was considered the NFL’s first football-specific facility. (AP Photo/Morry Gash, File)

FILE - In this Sept. 10, 2017, file photo, a flag is displayed on the field during the national anthem before an NFL football game between the Chicago Bears and the Atlanta Falcons, in Chicago. Opened in 1924 next to Lake Michigan, Soldier Field became host of the Bears in 1971. (AP Photo/Kiichiro Sato, File)