NFL reins in sack celebration by Vikings DE Allen

-No Fun League-

Allen said Monday that he found out before Minnesota's last game that his signature celebration is against league rules because he goes to the ground while doing it. He says touching the turf with his knee is considered unsportsmanlike conduct.

Allen said he didn't understand why he just learned about the ban since he's been celebrating each sack the same way for years. He joked that he should put a piece of cardboard underneath his knee to comply with the rule.