Doug Martin has tested positive for performance enhancing drugs and will serve a four-game suspension effective immediately.

"I was notified last week of a four-game suspension for violating the league's drug policy," Martin said in a statement. "My initial instinct was to appeal the suspension and finish the season with my teammates. However, after numerous discussions with people close to me -- including Coach (Dirk) Koetter -- I am starting the suspension immediately so I can enter a treatment facility and receive the help I truly need.

"On the field, I must be strong and determined to push through both pain and injuries to become an elite NFL running back. Off the field, I have tried that same approach in my personal life. My shortcomings in this area have taught me both that I cannot win these personal battles alone and that there is no shame in asking for help."

Martin was declared inactive for Week 16, which Koetter called a "coach's decision."

"I sincerely apologize to the Glazer family, general manager Jason Licht and the entire Tampa Bay organization, my teammates and our tremendous fans," said Martin, who wasn't at practice Wednesday. "This was not the season I envisioned and I have let everyone down, including myself. However, adversity yields opportunity and I ask for your support in my battle to overcome these personal issues."