They tied for the best record in the N.F.L. They earned home-field advantage throughout the playoffs. Their defense gives opponents nightmares and they have an offense loaded with quality skill players. But the Philadelphia Eagles, despite having all that on their résumé, head into Saturday’s divisional round matchup against the Atlanta Falcons as 3-point underdogs.

If Carson Wentz’s impact as the team’s starting quarterback was not fully understood when he sustained the season-ending tear of his left anterior cruciate ligament, it certainly is now. Once Super Bowl favorites, the Eagles are now expected to lose against the bottom-seeded team in the N.F.C. playoffs, even at the friendly (to them) confines of Lincoln Financial Field.

A top seed losing in their first playoff game is not without precedent — it has happened nine times since the current playoff format was adopted in 2002 — but it would sting even more for the loss to come at the hands of the second wild-card team. That has happened just four times in those 15 seasons, most recently when the sixth-seeded Green Bay Packers beat the top-seeded Falcons after the 2010 season.

If Philadelphia becomes the fifth team to suffer such an ignominious fate, it will probably be the result of Nick Foles’s having taken over at quarterback for Wentz. A former starter, Foles has appeared to be on the verge of stardom several times in the past, and before Wentz went down he seemed like an ideal backup to have in the event of a catastrophic injury.