The Minnesota Vikings hired a new coach in Mike Zimmer, and now the personnel is starting to change as well.

Linebacker Eric Henderson, who started 12 games for the Vikings this past season but had some run-ins with the law, was released by the Vikings, the team announced Friday.

Henderson, who played both middle and outside linebacker for the Vikings, played in 14 games in 2013 and had four sacks and two interceptions.

However, he was arrested a second time for suspicion of DUI in January.

Also, Vikings quarterback Matt Cassel has exercised his right to opt out of the final year of his two-year deal he signed with the Vikings last year, ProFootballTalk.com reported.

With his decision to void the final year of his contract, Cassel will become a free agent on March 11.

Cassel had until Friday to opt out. If he had decided not to opt out, the Vikings would have had until March to either pay Cassel a $500,000 roster bonus or release him, according to an ESPN.com report.

Cassel was due to earn $3.7 million with the Vikings next year.

---The Kansas City Chiefs released veteran cornerback Dunta Robinson, who signed a three-year contract with the team in 2013.

The cost-saving move will free up about $3 million from the Chiefs' salary cap for next season. Robinson's three-year deal was worth $13.7 million.

The 31-year-old played in just nine games and started two last season for the Chiefs.

--- The Detroit Lions re-signed center Dominic Raiola to a one-year deal, the Detroit Free Press reported Friday.

Raiola took a pay cut to remain with the Lions last year, earning the veteran's minimum of $950,000 last season. The Free Press reports that he is likely to receive a sizable raise.

Raiola started all 16 regular-season games for the Lions for the fifth straight season in 2013.

---Former South Carolina defensive end Jadeveon Clowney, who still hopes to be the No. 1 overall pick in the 2014 NFL Draft, said during a radio interview on Thursday that does not plan to have surgery on the bone spurs that bothered him during the 2013 season.

"If the team that gets me in the draft wants me to get (the surgery), I'll get it. If not, I won't," he said on The Dan Patrick radio show, according to The State newspaper of Columbia, S.C.

Clowney might get the surgery following his rookie season in the NFL. But for now he plans to participate in all drills at the NFL Combine.

Clowney is ranked as the No. 2 overall NFL prospect in the draft by NFLDraftScout.com, and he is No. 1 on Rob Rang's Big Board.

---Recently-retired tight end Tony Gonzalez told ESPN the Magazine that Atlanta Falcons teammate Matt Ryan is not an elite quarterback and that he was waiting to be traded during the season.

Gonzalez said that while Ryan is better than most quarterbacks in the NFL, he is not at the top tier yet.

Gonzalez also said he was open to being traded before the Oct. 29 deadline. At that point, the Falcons fell to 2-5 and on their way to a 4-12 record.

---The Green Bay Packers made several assistant coaching hires, the team announced.

Green Bay named Ron Zook assistant special teams coach, Sam Gash running backs coach, Alex Van Pelt quarterbacks coach, Winston Moss assistant head coach/linebackers, Scott McCurley assistant linebackers coach, Jason Simmons defensive/special teams assistant, John Rushing defensive quality control coach, Luke Getsy offensive quality control coach and Chris Gizzi strength and conditioning assistant.

---The Buffalo Bills announced that they promoted Jason Rebrovich to assistant defensive line coach.

Rebrovich spent his first season with the Bills last year as the team's defensive quality control coach. Rebrovich will work under defensive line coach Pepper Johnson.