The league announced the suspension on Friday. Nealy will not be paid during his suspension, but he is eligible to participate in all practices, offseason programs and preseason games.
Nealy was a member of the Vikings practice squad for six weeks last season. If he makes the team, he will be eligible for the Vikings' active roster on Sept. 29.
Nealy says he took a supplement with a banned stimulant. He says he takes responsibility for his actions and apologized to the organization and fans for the suspension.