(Reuters) - New York Jets tight end Kellen Winslow Jr. has been suspended by the National Football League (NFL) without pay for four games for violating the league's policy on performance enhancing substances.
The 30-year-old, a Pro Bowl selection in 2007 who is the leading receiver for the Jets this season with 17 catches, will begin his suspension immediately, the league said on Friday.
"It came as a huge surprise to me when I learned that I tested positive for a banned substance," Winslow, who will initially miss Sunday's game against the Pittsburgh Steelers, 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 the NFL policy is very strict, so I am accountable for the results."
Winslow, who is on a one-year contract with the Jets, will be eligible to return to the team's active roster on November 4, after their Week 9 game against the New Orleans Saints.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Mark Lamport-Stokes)