By Peter Gleason

The Eagles are on the verge of playing their first playoff game in four seasons when they take on the Atlanta Falcons Saturday at the Linc in the divisional round.

And they will make history:

No other No. 1 seed in 42 years has ever begun the playoffs as an underdog.

The Falcons opened as 2.5-point favorites.

Since 1975, when the NFL began basing home-field advantage on teams’ regular-season winning percentage, no No. 1 seed has ever been an underdog in its first playoff game, according to ESPN Stats & Information. Barring dramatic line movement, the Eagles will be the first.

The Eagles lost quarterback Carson Wentz to a knee injury in early December and haven’t looked the same team with backup Nick Folesunder center.

Westgate Superbook oddsmaker Ed Salmons estimates the Eagles, with a healthy Wentz, could have been as much as 6.5-point favorites over the Falcons. Without him, Salmons and other Las Vegas oddsmakers say they would be an underdog to any other team in the NFC playoffs this week.

Since the NFL went to a 12-team playoff format in 1990, only four No. 1 seeds have been less than 3-point favorites in their first game. Most recently, the 2010 Falcons were only 1-point favorites over the Green Bay Packers in a divisional game. The Packers won 48-21.

Bettors were siding with the Falcons over the Eagles early. The line had already grown to Atlanta minus-3 on Sunday morning at some sportsbooks.

“The early action, it’s pretty much all on Atlanta,” Salmons told ESPN on Sunday.. “The public is going to bet Atlanta.”

Las Vegas sportsbook operator CG Technology also reported early interest in the Falcons.

“We might not take a bet on the Eagles until it hits (Atlanta minus) 3.5,” CG Technology’s Jason Simbal said.