Veteran Seattle Seahawks safety Kam Chancellor has likely played his last down in the NFL. He never used the word "retire" in his tweets on Sunday, but he seemed to indicate that the neck injury he suffered in November has prematurely ended his career at age 30.
And what a career the former fifth-round pick had. Let's take a look back at what made the 6-foot-3, 225-pound monsterback a consistent -- and feared -- defender. From his ability to drop the hammer on contact to his versatile skill set, Chancellor was a vital part of the "Legion of Boom," a unit that set the bar for secondary play in the NFL.
1. A clinical tackler
Every defensive back coach in football stresses tackling with the safety position. It's a must. Be physical at the point of attack and wrap up. Chancellor took that to another level. This is stuff for the teaching tape. And it's the same film I've shown as a high school coach. The shoulder pad to thigh board/strike zone, the wrap, the drive of the legs. If you wanted to improve the tackling in your secondary, you had to go toss on some clips of Chancellor. He closed the door on the run game, made plays in space and patrolled the middle of the field. The guy was a walking clinic on how to tackle.
2. Line him up anywhere on the field
With that ultra-rare combination of size and closing speed, Chancellor was really three players in one. Just think of the strong safety rolled down, or a linebacker creating havoc, or a deep defender driving on the rock. That's peak versatility in a system that catered specifically to his talent. Chancellor was scripted chaos, a hybrid defender with thunder in his pads along with the versatility to play both the run and the pass. Smart, tough and physical. That's how I've described his game.
3. That hit in Super Bowl XLVIII
Early first quarter against the Broncos. A crossing route -- Peyton Manning to Demaryius Thomas. And there's Chancellor lying in the weeds. Ballgame. The hit? Physical and clean. Read the quarterback and break on the throw. But that shot Chancellor delivered was also a perfect example of the defensive culture on the Seahawks' championship squad. And I'll always remember Chancellor using his pads to make Thomas sit down on the turf. It sent a message. Time to warm up the bus.
4. The impact of the 'Legion of Boom'
I love watching the tape from the Seattle defense's peak. The Seahawks dictated the flow of the game, and their Cover 3 wasn't a complicated scheme. They had the key pieces in the back end with Chancellor, Earl Thomas and Richard Sherman, and coach Pete Carroll & Co. coached up the importance of technique. Everyone wanted to copy the Seahawks' style of play. Thomas was the gatekeeper of the post. Sherman locked down receivers outside the numbers. And Chancellor? He simply wrecked things. Similar to Lovie Smith's top-tier Bears defenses, that Seattle group reminded us that you don't need all this wild stuff in the game plan. It's still fundamentals, tackling, speed and an identity built on intimidation. That always wins over X's and O's.
5. The pain of football
Chancellor is walking away from football after an eight-year run with four Pro Bowl appearances. Not bad for a Day 3 pick out of Virginia Tech. And his style of play will be remembered for a long time. Run, hit and generate maximum disruption.
But Chancellor's career is also a reminder of the risk/reward struggle for NFL players. There is great opportunity playing professional football. Money. Prestige. But this game also bangs up players and gives them injuries they'll have to treat the rest of their lives. Knees, shoulders, neck for Chancellor -- every player pays the price before it's time to shut it down for good.
ESPN.com NFL analyst Matt Bowen played seven seasons as a defensive back in the NFL.