Justin Blackmon has been suspended for the first four games of the 2013 NFL season after being found to have breached the league's substance abuse policy.
The Jacksonville Jaguars wide receiver will be able to return to the team's roster on September 30 after their game against the Indianapolis Colts.
The 23-year-old said in a statement released by the Jags: "I've made a mistake and I have no excuse. I am truly sorry and disappointed in myself for putting the Jaguars in this situation, and I look forward to putting this behind me and maturing and growing as a person.
"I will have a productive training camp and pre-season with my team, and during the suspension I will work hard to stay in top football shape and be ready to help the Jaguars when I return.
"I have chosen to be accountable for my poor decision, and I sincerely apologise to my teammates, coaches, the front office and Jaguars fans for the impact of my mistake on the team."
Blackmon had a strong finish to the 2012 campaign, scoring four touchdowns for Jacksonville in their last seven games of the season.