"The substances of abuse policy requires everyone to comply with the rules," Miller said in a statement released by the NFL Players Association. "Although my suspension doesnt result from a positive test, there is no excuse for my violations of the rules. I made mistakes and my suspension has hurt my team, Broncos fans, and myself. I am especially sorry for the effect of my bad decisions on others.
"I will not make the same mistakes about adhering to the policy in the future. During my time off the field, I will work tirelessly and focus exclusively on remaining in peak shape. I look forward to contributing immediately upon my return to the field and bringing a championship back to the people of Denver."
Miller led the Broncos with 18.5 sacks last season.
In two NFL seasons, the former Butkus Award winner from Texas A&M has 132 tackles, 30 sacks, one interception and eight forced fumbles.