The NFL regular-season schedule comes out tomorrow, but we already know something big about the postseason. The league said today that ESPN will air a wild card game during the first weekend of the playoffs in early January. The milestone game will mark the first postseason NFL game on pay TV — and should draw astronomical ratings for the cable universe. Last season’s wild card weekend was a goldmine for NBC, CBS and especially Fox, whose 49ers-Packers contest was the most-watched wild card game on any network since the Reagan administration with 47.1 million viewers. Even that weekend’s lowest-rated game — in which the Colts erased a four-touchdown deficit to stun the Chiefs — drew 27.6 million. But that’s more than the largest cable TV audience ever: the 2011 Auburn-Oregon college football title game, which pulled in 27.3 million viewers for ESPN. The sports network, which carries Monday Night Football games, signed an eight-year contract extension with the NFL in 2011 to keep the lucrative franchise through the 2021 season. That pact — which also covers international TV rights to NFL games including the Super Bowl — included an option for the league to give a postseason game to ESPN. The network’s MNF team of Mike Tirico and Jon Gruden will call the Wild Card game, which also will be available via WatchESPN.