He will be eligible to return October 20 at the New York Giants.
Peterson will lose $3,882,352 in wages, ESPN's Adam Schefter reported. "As we all do, he understands that regardless of intent he is ultimately responsible for everything he puts in his body", the Cardinals said in a statement.
Peterson recorded 54 tackles and two interceptions in 2018. "Our coaching staff and our players are now aware that we will have to play the first six games without Patrick and they understand they have to rise to the challenge that it presents".
The suspension will represent the first games missed during Peterson's nine-year career.
An eight-time Pro Bowler, Peterson has been the subject of trade rumors for some time.
After Peterson backed off his midseason trade demand previous year, he said he wanted to follow in Larry Fitzgerald's footsteps as the face of the franchise.
How much do Cardinals fans want to stand behind Peterson now?
Peterson can participate in all offseason workouts and preseason games.
"First of all, I do not know the details of Patrick Peterson's suspension", said ESPN's Dan Graziano while joining Bickley & Marotta Thursday. His suspension might be the reason that hasn't happened yet. It's unclear what Peterson took, or anything like that, but social media reacted just how you'd expect, with an old quote about Tom Brady being brought back to the forefront. "I communicated with Patrick". Peterson believed he could save at least $2 million with a reworked contract, according to Gambadoro. The suspension was initially said to be eight games, but the National Football League insider later reported that it would be six after Peterson dropped his appeal. Arizona drafted him with the No. 5 pick in 2011 out of LSU.