Antonio Gates has been suspended four games for violating the NFL's policy on performance-enhancing substances.

In a statement, Gates said he did not knowingly take a banned substance, but he acknowledged he did take supplements this offseason and would accept the consequences.

"I take full responsibility for my actions," Gates said. "I'd like to express my sincere apologies to the Chargers, my teammates, coaches, fans and the league who have always supported me and expected and gotten nothing but the highest level of integrity from me."