After winning Super Bowl LII, the Eagles may not make the 2018 playoffs.
The last Super Bowl Champion to miss the playoffs was the Denver Broncos. After winning Super Bowl 50 in 2015, the Broncos went 9–7 in 2016 and failed to secure a playoff spot behind the Raiders and the Chiefs, who both went 12–4 on the season.
Kansas City went on to win the AFC West, breaking a five-year win streak by the Broncos.
The Patriots won the Super Bowl during the 2016 season and proceeded to finish 13–3 in 2017 en route to a second straight championship appearance, where they fell to the Eagles.
Philadelphia has struggled to regain the momentum of it's 2017-18 season that culminated in a Super Bowl Championship. They currently sit at 6–7 behind the Cowboys in the NFC East through Week 14. With playoff hopes dwindling, the Eagles might follow in the Broncos 2016 footsteps.