The Philadelphia Eagles are the reigning Super Bowl champions.

But there is plenty of reason for concern, and it starts with one number: 4,390.

The Athletic shared the statistic that the Eagles have lost 4,390 snaps from last season's defense.

"Four thousand, three hundred and ninety seems like a big number, but Howie Roseman isn’t even worried," writes The Athletic. "That’s the number of defensive snaps the Eagles lost from last season with the departure of Josh Sweat, Milton Williams, C.J. Gardner-Johnson, Darius Slay, Isaiah Rodgers and Oren Burks."

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Those are some serious stars no longer around.

The Eagles still have tons of talent, including young players getting better like Cooper DeJean and Quinyon Mitchell.

But it's really, really hard to repeat as a Super Bowl champ, especially with losses like that.

Given Washington's emergence in the NFC East, too, Philadelphia looks like it'll be in for some serious battles this season.

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