Josh Gordon has apologised for breaching the NFL's substance-abuse policy after receiving a two-game suspension.
The Cleveland Browns wide receiver will miss the start of the 2013 season, having taken a throat medicine that contained the drug codeine.
The 22-year-old said in a statement: "The policy terms are strict about unintentional ingestion, but the NFL has not imposed the maximum punishment in light of the facts of my case. Therefore, I have chosen to be immediately accountable for the situation.
"I sincerely apologise for the impact on my team, coaches, and Browns fans. I look forward to working hard in training camp and pre-season, and contributing immediately when I return in week three."
Gordon recorded 805 yards and five touchdowns during his first season in the NFL.