According to a source, Guion was notified of the three-game ban this week, and his agent and lawyers immediately began preparing their appeal. The NFL does not announce suspensions until the appeal process has been completed, according to league spokesman Greg Aiello.
The Packers and Guion have been bracing for a suspension ever since his February arrest on charges of possession of marijuana and a firearm, but they were hoping he would be suspended for only a game or two after Guion paid a $5,000 fine in a plea deal to avoid prosecution.
Neither Guion nor his agent, Seth Katz, could be reached for immediate comment Thursday, and it's unknown when the appeal hearing will be held.
The Packers re-signed Guion to a one-year, $2.75 million contract shortly after the case was settled in March. If Guion's suspension is not reduced, he will lose nearly a half-million dollars. He would lose three game checks totaling $264,706. He also has a roster bonus for $71,875 for each game he plays in, meaning he would lose another $215,625.
Guion is still fighting to recover $190,028.81 in cash and his 2015 Dodge Ram truck that police in Starke, Florida, seized during his arrest. Guion is suing to get those possessions back.
Guion is a projected starter at one of the two defensive end positions in defensive coordinator Dom Capers' 3-4 defense. If Guion's suspension holds up, the Packers will be without two defensive linemen to start the season.