NEW YORK—Saying that it is the perfect way to further increase the sport’s popularity, NFL commissioner Roger Goodell announced Monday that the league will soon begin holding a regular-season game deep within the Earth’s inner core. “This game represents an opportunity to bring the great sport of football over 3,000 miles below Earth’s crust,” said Goodell, adding that the primetime event in the planet’s 10,800-degree, nickel-iron core will be scheduled as a regular-season matchup between two non-divisional opponents.