Ian Rapoport of the NFL Network reported the amount Friday after Williams posted about the punishment Thursday on Twitter:
The 25-year-old edge-rusher was also called for roughing the passer on the fourth-quarter play as part of the Jags' 14-10 exhibition victory.
Although the call generated controversy amid concerns about the new rule about leading with the helmet, the flag was more likely based on the way Williams forcefully took Kessler to the ground.
Will Brinson of CBS Sports noted defenders are restricted from "stuffing" a quarterback to the field and aren't allowed to "land on top of him with all or most of [their] weight."
So, while it would otherwise be a textbook tackle by Williams, the fact it was on a QB and he drove forward to complete the hit would suggest it was the right call by the letter of the law. Whether it's a good rule is a separate debate.
Williams, who's competing for a roster spot behind starters Ben Gedeon and Anthony Barr at outside linebacker, has tallied three combined tackles so far in the preseason.
The Vikes play their third exhibition contest Friday night against the Seattle Seahawks.