Winslow leads the Jets with 17 catches and is tied for the team lead with two touchdown receptions this season. Winslow was already listed as doubtful for this week's game against the Pittsburgh Steelers and hasn't practiced all week because of an injured right knee.
Winslow's suspension will cost him $197,647 in salary. He will be eligible to return Monday, Nov. 4.
“It came as a huge surprise to me when I learned that I tested positive for a banned substance," Winslow said in a statement. "I have investigated all possible sources since learning of the positive test, including possible medical causes, but frustratingly I do not know the source. I do not take supplements that list any banned ingredients, but NFL policy is very strict, so I am accountable for the results. I sincerely apologize to my teammates, coaches and Jets fans for this situation. I will work extremely hard during this time away from the field and look forward to contributing as soon as the suspension ends."