Johnson will be eligible to return to the active roster on Monday, September 29 following the Eagles' September 28 game against the San Francisco 49ers.
Johnson is eligible to participate in all offseason and preseason practices and games, inluding Training Camp.
The team released the following statement: "We’re very disappointed to learn of his suspension. We have spoken to Lane about the details of the suspension. He understood what he did wrong and took full responsibility. The key for him, however, is to learn from that mistake and move forward with his preparation for the 2014 season.”
Johnson said the following: "In April while training, I mistakenly and foolishly put a prescribed medication in my body to help with a medical issue. I mistakenly failed to clear it with Eagles trainers and check the NFL list of banned substances. I am extremely sorry for this mistake and I will learn from it and be smarter in the future.
"I would like to sincerely apologize to Mr. Lurie, Howie Roseman, Coach Kelly and his staff, my teammates and our amazing Philadelphia Eagles fans. This will be very hard on me to not be battling with my teammates for four games - but I will be ready and better than ever when I return."