This Dec. 18, 2016 photo shows Tampa Bay Buccaneers' Doug Martin (22) carrying the ball in the first half of an NFL football game against the Dallas Cowboys in Arlington, Texas. Martin has been suspended four games for violating the NFL's policy on performance enhancing substances and said Wednesday, Dec. 28, 2016 he's entering a treatment facility rather than appeal the ban. (AP Photo/Ron Jenkins)
This Dec. 18, 2016 photo shows Tampa Bay Buccaneers' Doug Martin (22) carrying the ball in the first half of an NFL football game against the Dallas Cowboys in Arlington, Texas. Martin has been suspended four games for violating the NFL's policy on performance enhancing substances and said Wednesday, Dec. 28, 2016 he's entering a treatment facility rather than appeal the ban. (AP Photo/Ron Jenkins)

Tampa, Fla. — Tampa Bay running back Doug Martin has been suspended four games for violating the NFL’s policy on performance enhancing substances and said Wednesday he’s entering a treatment facility rather than appeal the ban.

The two-time Pro Bowl selection, slowed by a hamstring injury this season after rushing for 1,402 yards in 2015, will miss Sunday’s regular-season finale against Carolina.

He also sat out last week’s 31-24 loss at New Orleans after being declared inactive against the Saints, though that game won’t count against the penalty.

Martin said in a statement that he learned of the suspension last week and that his “initial instinct” was to “appeal the suspension and finish the season with my teammates.”

The fifth-year pro said he decided to enter a treatment facility “and receive the help I truly need” after discussing the matter with people close to him, including Bucs coach Dirk Koetter.

“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,” Martin said in the statement released through the team.

“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.”

The 27-year-old running back was excused from practice on Wednesday.

Ravens WR Likely to Retire

Owings Mills, Md. — Steve Smith sounds like a man who’s ready to close the door on an NFL career that has spanned 16 seasons and taken him well beyond his 37th birthday.

“Whether you want to or not, you’ve got to move on,” Smith said Wednesday. “It’s part of life. The world still turns.”

The five-time Pro Bowl receiver will play in his 230th NFL game on Sunday when the Baltimore Ravens finish the season against the Cincinnati Bengals.

Standing in front of the media wearing a Darth Vader costume, Smith said he’s “about 89 percent sure” it will mark the end of his stellar career.

He used that number because he wears No. 89.

Though Smith spoke with deep emotion during his 10-minute session, he did not formally announce his retirement. He already did that once before, prior to the 2015 season, but ended up changing his mind after tearing his Achilles tendon in Week 7.

Smith ranks seventh in NFL history with 14,697 yards receiving and is 12th with 1,028 receptions.

Panthers LB Out

Charlotte, n.c. — Coach Ron Rivera said he will not play three-time All-Pro middle linebacker Luke Kuechly in the team’s season finale against the Tampa Bay Buccaneers with the Panthers out of playoff contention and his star defender recovering from a concussion.

Kuechly was cleared from the NFL’s concussion protocol three weeks ago, but Rivera has elected not to play him as a precautionary measure.

Kuechly has not played since suffering his second concussion on Nov. 17 against the New Orleans Saints.

Jets’ Mangold Not Retiring

Florham Park, n.j. — Nick Mangold has no plans to call it a career.

The New York Jets center faces an uncertain playing future, but retiring is far from his thoughts despite an injury-filled 11th NFL season that ended three weeks ago when he was placed on injured reserve.

“Shoot, I love football,” said Mangold, speaking to reporters on Wednesday for the first time since being shut down. “I miss it dearly, so I’m planning on playing.”

Mangold played in eight games after spraining his right ankle against Baltimore on Oct. 23, suffering a setback in his rehabilitation a few weeks later, then re-injuring it against Indianapolis on Dec. 5.

Browns QB Still in Protocol

Berea, Ohio — Browns starting quarterback Robert Griffin III remains in concussion protocol and could miss Sunday’s season finale in Pittsburgh.

He was injured in the fourth quarter in last week’s win over San Diego and replaced by rookie Cody Kessler, who finished off Cleveland’s first victory in 2016.