Minnesota Vikings defensive end Spencer Nealy was suspended four games for violating the NFL's policy on performance enhancing substances, the league announced Friday.

The 24-year-old Nealy, an undrafted free agent out of Texas A&M, did not play in a game last season.

Nealy will be eligible to return to the Vikings' active roster on Monday, Sept. 29 following the team's Sept. 28 game against the Atlanta Falcons.

Nealy is eligible to participate in all offseason and preseason practices and games.

The NFL Players Association released a statement on behalf of Nealy:

"Recently I learned from the NFL that I tested positive for a stimulant that is banned under the NFL policy. I worked with my agent and the union to investigate the test results, and I learned that a supplement I took contained a banned stimulant. I understand that the NFL policy is very strict, and I take responsibility. I'm very sorry for the impact of this situation on my teammates, the Vikings organization and Vikings fans. I will work extremely hard during training camp, and during the suspension, I will stay in top shape and will be ready to contribute upon my return."