BALTIMORE -- Ravens defensive tackle Haloti Ngata was suspended without pay for four games Thursday for violating the NFL's policy on performance-enhancing substances.
Ngata will miss the rest of the regular season but will be eligible for the playoffs, the league said.
Ngata said in a statement released by the team that he took Adderall, a drug used to treat attention deficit hyperactivity disorder.
"I made a mistake, and I own this," he said.
The suspension costs Baltimore one of its defensive stars as the Ravens compete for a playoff berth. They're 1 1/2 games behind the Bengals in the AFC North and one of six 7-5 teams tied for the second wild-card spot.
"I am deeply sorry and broken up over this," Ngata said. "I let down my family, my teammates, Ravens fans and myself. My hope is that the Ravens make the playoffs, and I believe they can do this. And then I can come back and help us win."
Ravens general manager Ozzie Newsome said, "We are disappointed with Haloti, but no more than he is with himself,"
Ngata has two sacks, two interceptions and two forced fumbles in 12 games this season. Rookie Timmy Jernigan, a second-round pick out of Florida State, likely will take his place in the starting lineup.
"I'm definitely prepared. That's all I've wanted ever since I've been here is a shot," Jernigan said after Thursday's practice. "Playing 15, 17 snaps a game, it's tough to get going, but now I kind of have an opportunity to show the world that I can actually (play)."
Baltimore defensive coordinator Dean Pees knows what it's like to have to replace a standout player, and he's prepared to move on without Ngata.
"It's disappointing and all that, but it would be the same thing if we lost anybody due to injury," Pees said. "You never want to lose anybody for any reason at all, but that's the name of the game. Everybody goes through stuff at this time of year.
"A couple years ago, we played 10 games without Ray Lewis, played eight games without (linebacker Terrell) Suggs. We're going to play four games without Haloti. Next guy up. Let's play."
The Ravens face Miami on the road Sunday, so it's likely Pees would have used a variety of defensive linemen even if Ngata was available.
"I think it's going to be a committee effort this week down there anyhow in the 80-degree weather," Pees said. "Late in the season and stuff, we roll guys a lot the way it is, and this game wouldn't have been any different."
The NFL has been concerned about an increase in Adderall use. Its drug tests don't differentiate between Adderall and other amphetamines, which can help with concentration and stamina. Players diagnosed with ADHD can apply for a therapeutic use exemption that permits them to take the drug.
Under its agreement with the union, the NFL doesn't identify the substance when a player is punished. In the past, suspended players frequently blamed Adderall, but the league could not confirm or deny whether that was the basis for the positive test.
But under the new drug agreement announced earlier this season, the NFL can now disclose information to "correct inaccurate public claims made by that player or his representatives about the discipline."