Baltimore Ravens defensive lineman Haloti Ngata has been suspended for the remainder of the season by the NFL for violating the league’s policy on performance-enhancing substances.

The league does not release the details of the failed test that triggered the suspension, but Ngata said he took Adderall, which requires a prescription on record with the NFL because it is on the league’s list of banned substances.

“I made a mistake, and I own this. I took Adderall and take full responsibility for doing this,” Ngata said in a statement released by the Ravens. “I am deeply sorry and broken up over this. 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.”

The Ravens (7-5) play at Miami on Sunday and have a difficult road to the postseason in a packed playoff race in the AFC.

Ngata is eligible to return to the roster Dec. 29, the day after the season ends. He will be available for the playoffs if the Ravens qualify.

—The disappointing 2014 season apparently is over for Houston Texans outside linebacker Jadeveon Clowney, the No. 1 pick in the draft.

Coach Bill O’Brien announced that Clowney will be placed on injured reserve because of a right knee injury. Clowney is scheduled to have another surgery on that knee.

Clowney, 21, played in just four games in his rookie season, recording seven tackles and no sacks.

—Atlanta Falcons safety William Moore said he was fined $22,050 by the NFL for a hit he put on Arizona Cardinals receiver Jaron Brown on Sunday. Moore said he would appeal.

Moore led with the crown of his helmet on the hit, which is why he was fined. Moore had missed the previous seven games with a shoulder injury.

Last year, Moore was fined nearly $75,000 for violations, and he said he was trying to change the way he tackled to avoid those steep fines.

—The San Diego Chargers placed guard Ryan Miller on the non-football injury list and promoted lineman Jeff Baca from the practice squad.

The Chargers signed lineman Bryce Quigley to the practice squad.

Miller, 25, suffered a concussion Wednesday when he slipped and fell at practice. Miller missed the 2013 season after struggling to recover from a concussion suffered in training camp with the Cleveland Browns.

—The Denver Broncos signed kicker Brandon McManus to their practice squad and released defensive end Gerald Rivers on Monday, according to the Denver Post.

McManus, who replaced Matt Prater this season, was released last week after making just 9 of 13 field goals. The Broncos replaced him with Connor Barth, who hit all five of his attempts in his first game, a 29-16 win over the Kansas City Chiefs on Sunday.

—Minnesota Vikings wide receiver Cordarrelle Patterson is no longer a starter.

Offensive coordinator Norv Turner confirmed this week that Charles Johnson has moved ahead of Patterson at the “X” spot.

Patterson did not play in the first half of the Vikings’ win over the Carolina Panthers on Sunday.

The former first-round draft pick has 30 catches for 350 yards and one touchdown in 12 games this season.

—New York Jets wide receiver Greg Salas scored his first NFL touchdown on Monday, but he won’t be playing anymore this year as the Jets placed him on injured reserve on Thursday because of a hamstring injury.

Wide receiver Chris Owusu was called up from the practice squad to replace Salas on the roster.

—The New England Patriots placed wide receiver Aaron Dobson on injured reserve with a hamstring injury, ending his season.

Dobson had three catches for 38 yards this season. He played just four snaps against the Green Bay Packers on Sunday, but injured his hamstring on one of them.

—Chicago Bears wide receiver Alshon Jeffery is listed as questionable because of a hamstring injury but is expected to play against the Dallas Cowboys on Thursday night.

Jeffery sat out Tuesday’s practice and was restricted on Wednesday. The 24-year-old leads the Bears with 854 receiving yards this season.

—The post-halftime blackout at the Superdome in New Orleans was just one of several security concerns surrounding Super Bowl XLVII, according to a report.

While the blackout after Beyonce’s halftime show created brief concerns about foul play and possible terrorism, NBC Washington’s News4 I-Team uncovered other incidents surrounding the game between the Baltimore Ravens and San Francisco 49ers in February 2013.

A two-year review of law enforcement communication in the hours before and during the Super Bowl revealed several threats of explosives and a case of stolen police guns.

Although the timing of the stadium power outage was suspicious considering the bomb threat, the blackout was not deemed to be connected to any of the events and was blamed on a breakdown in the Superdome’s power system.

—Former quarterback Ryan Leaf, still remembered as one of the NFL’s biggest busts, was released on parole from a Montana prison on Wednesday, the Great Fall Tribune reported.

Leaf, the No. 2 overall pick in 1998 by San Diego, served about half of his five-year sentence on drug and burglary charges. He also was dismissed from a drug treatment program for threatening a staff member.

Leaf was required to complete a chemical dependency program to be granted parole.