Jackson is appealing his suspension, a source told ESPN’s Jeremy Fowler.
Jackson was ejected from Sunday’s game against the Green Bay Packers for his sideline hit on Packers tight end Luke Musgrave in the fourth quarter. It was the second time this season he was ejected for an illegal hit.
“On the play in question, you delivered a forceful blow to the head/neck area of a defenseless receiver, when you had the time and space to avoid such contact. You could have made contact with your opponent within the rules, yet you chose not to,” vice president of football operations Jon Runyan wrote in a letter to Jackson.
In his letter, Runyan noted that Jackson has had multiple instances of violations of player-safety rules.
Entering Sunday’s game, he had been fined four times this season for unnecessary roughness — for a total of $89,670.
If Jackson’s four-game suspension is upheld, he will miss games against the Kansas City Chiefs, Buffalo Bills, Minnesota Vikings, and Cleveland Browns. He would be eligible to return to Denver’s active roster on Monday, Nov. 27.
On Sunday, Musgrave caught an 18-yard pass from Jordan Love and, as linebacker Alex Singleton closed in, Jackson arrived and knocked Musgrave to the turf. Two flags were immediately thrown. After a brief discussion among the officials, referee Alex Kemp announced that Jackson had been ejected in addition to the 15-yard penalty.
Some Broncos players said they believed Jackson had led with his shoulder and hit Musgrave slightly below the head and neck area. Green Bay players on the sideline near the hit shouted at Jackson after the play as Packers coaches quickly got between Jackson and the group.
ESPN’s Jeff Legwold contributed to this report.