The Seattle Seahawks signed defensive end Cliff Avril on Friday to a four-year contract extension worth $28.5 million, with $16 million guaranteed.

Avril, who was set to become a free agent at the end of the season, joined the Seahawks in 2013. The 28-year-old pass rusher has totaled 40 tackles, 12.5 sacks and six forced fumbles over 29 games with Seattle. He has 20 tackles, 4.5 sacks, one forced fumble and one fumble recovery this season, and he leads the team with 17 quarterback hits.

“Cliff has been instrumental in what we’ve been building on the defensive side of the ball and we are excited that he’ll be with us for another four years,” general manager John Schneider said in a statement. “He has been relentless in his approach to the game and his passion for winning is contagious. This is another great day for the Seahawks and the 12s.”

Avril’s new deal comes just one day after the Seahawks signed linebacker K.J. Wright to a four-year, $27 million contract extension.

—Carolina Panthers quarterback Cam Newton is listed as probable and expected to start Sunday against the Cleveland Browns — only 12 days after a rollover car accident.

Newton missed last week’s win over the Tampa Bay Buccaneers after he suffered two fractures to the transverse process in his back. The two-time Pro Bowler returned to practice Wednesday. Backup quarterback Derek Anderson started against the Bucs.

— San Diego Chargers quarterback Philip Rivers is expected to play Saturday against the San Francisco 49ers, but running back Ryan Mathews and wide receiver Keenan Allen will not.

Rivers, dealing with a back and rib injury, is listed as probable. He missed practice Wednesday for the first time since 2007, but he was back Thursday and Friday.

Mathews (ankle) and Allen (collarbone, ankle) are listed as out.

—The Buffalo Bills activated running back C.J. Spiller from the injured reserve/designated for return list.

Spiller is listed as probable and expected to play against the Raiders in Oakland on Sunday.

The 27-year-old Spiller has missed the last seven games with a broken clavicle. He was a limited participant in each practice this week.

—Minnesota Vikings linebacker Anthony Barr will have season-ending knee surgery, coach Mike Zimmer said.

Barr, who was the ninth pick in the draft this year, missed the last two games with the injury, which Zimmer called a “slight meniscus tear.”

Barr finished his rookie season with four sacks, three interceptions and two forced fumbles.

— The Washington Redskins placed safety Brandon Meriweather on injured reserve, meaning he will miss the team’s final two games of the season.

The team signed linebacker Steve Beauharnais to take Meriweather’s roster spot.

Meriweather had missed the last two games with a toe injury, and he had a setback in practice Wednesday that led to an MRI. He finished with 55 tackles, three sacks and three forced fumbles.

—Washington wide receiver Santana Moss was fined $22,050 by the NFL on Friday for directing abusive and insulting language toward a referee.

Moss was ejected from the Redskins’ 24-13 loss to the New York Giants last Sunday after he argued vehemently when referee Jeff Triplette reversed a touchdown run by quarterback Robert Griffin III at the end of the first half.

Among other fines reported Friday:

–Cleveland Browns linebacker Barkevious Mingo was docked $16,537 for a helmet-to-helmet hit on Cincinnati Bengals quarterback Andy Dalton;

–San Francisco 49ers safety Eric Reid was fined $10,000 for an unnecessary roughness penalty he received for hitting Seattle Seahawks wide receiver Doug Baldwin out of bounds;

–Tennessee Titans defensive tackle Jurrell Casey was assessed $8,268 for punching New York Jets quarterback Geno Smith in the head.

–New England Patriots cornerback Brandon Browner was fined $8,268 for shoving Miami Dolphins receiver Brandon Gibson to the ground, and Gibson was fined $11,025 for taunting Browner.

—While discussing North Korea’s cyber-attack and Sony’s cancellation of the release of “The Interview,” President Barack Obama apparently confused actor James Franco with Baltimore Ravens quarterback Joe Flacco.

“I think it says something interesting about North Korea that they decided to have the state mount an all-out assault on a movie studio because of a satirical movie starring Seth Rogen and James Flacco,” Obama said.

Social and mainstream media were all over Obama’s faux pas.

A fake James Flacco account on Twitter offered this: “I’d be more bummed about Sony yanking my movie, but I’m having the best season of my career.”

—Short a defensive lineman after releasing Ray McDonald earlier this week, the San Francisco 49ers promoted nose tackle Mike Purcell from the practice squad.

Purcell, an undrafted player out of Wyoming in 2013, had spent the two last seasons on the practice squad.

McDonald was released Wednesday after he was identified as a suspect in a sexual assault case.