Arizona Cardinals star wide receiver DeAndre Hopkins has been suspended six games for violating the NFL’s policy on performance-enhancing drugs, the league announced Monday.

Hopkins’ brand manager, Doug Sanders, wrote in a text message to ESPN’s Adam Schefter that a test in November returned “trace elements of a banned substance” and that tests in both the month before and after were negative.

“I was confused and shocked,” Hopkins tweeted later. “I am very mindful of what I put in my body and have always taken a holistic approach, so I am working with my team to investigate how this could’ve happened.

“But even as careful as I have been, clearly I wasn’t careful enough. For that, I apologize to Cardinals fans, my teammates, and the entire Cardinals organization. I never want to let my team down. I fully intend to get to the bottom of this. As soon as I have more information I will share it.”

The suspension comes four days after the Cardinals traded their first-round pick in the 2022 draft to the Baltimore Ravens on Thursday for wide receiver Marquise Brown.

Hopkins will be allowed to play during the preseason and practice with the team until the beginning of the 2022 regular season.

Hopkins, a three-time first-team All-Pro and five-time Pro Bowl selection, will turn 30 on June 6 and is coming off an injury-riddled season that led to the lowest output of his career.