Kam Chancellor, the safety who helped set the tone for one of the best defenses in NFL history, will not be able to play for the Seahawks in 2018. With training camp opening Thursday, that news became official with Seattle placing Chancellor on the reserve/physically unable to perform list. That designation officially ends Chancellor's season and means he will not count towards the 90-man roster.

Chancellor's impact on the team has been felt on and off the field over the past eight seasons, never more so than in big games when he seemed to be at his best. Four-and-a-half years ago, Chancellor and Demaryius Thomas met at the 40-yard line at MetLife Stadium, the Seahawks safety held his ground, while the Denver Broncos receiver stumbled backward nearly 5 yards on his way to the turf.

Following Denver's third-play from scrimmage in Super Bowl XLVIII, Chancellor celebrated with Earl Thomas and Richard Sherman, the Broncos were on their way to a three-and-out, and already the tone had been set. Yes, the Broncos record-setting offense might gain some yards and complete some passes, but it was going to be a long, painful evening facing Seattle's defense.

"It just sends a message," Chancellor said following Seattle’s 43-8 victory in Super Bowl XLVIII. "Any time you come across that middle, you've got a chance of getting wrecked. That's the way we play on defense. We play physical, we want to instill our will… We did exactly what we said we were going to do. We finished business."

Tone-setter, leader, enforcer, playmaker and so much more, Chancellor became over the course of an eight-year NFL career one of the best and most important players in Seahawks history. Unfortunately for Chancellor and the Seahawks, the man known as Bam Bam will not be able to play this season, the result of a neck injury sustained last season. Last summer, Seahawks coach Pete Carroll explained what Chancellor, who was part of Carroll and general manager John Schneider's first draft class, meant to the Seahawks.

"I admire the heck out of this guy," Carroll said. "This is a great kid, he's a great leader, he's a tough guy, he's a heart-and-soul guy. He's a fifth-round draft pick who broke all the way through from that to become a great football player and leader in our program."

After spending his rookie season playing mostly on special teams while learning under veteran safety Lawyer Milloy, Chancellor took over a starting job in 2011 and not only became a difference maker on the field, but also a leader despite some initial reluctance to take on that role.

Chancellor went on to earn Pro-Bowl honors four times in his career was named second-team All-Pro twice, and while those honors are impressive, they only begin to show the impact Chancellor had on the franchise. While helping anchor a defense that allowed the fewest points in the league for four straight seasons, Chancellor served as a team captain on multiple occasions and is one of only two players in franchise history, along with fullback Mack Strong, to win the Steve Largent Award more than once.

Chancellor was also a player who saved his best play for the biggest games, putting together an MVP-worthy performance in Super Bowl XLVIII with a team-high 10 tackles, an interception and that game-defining hit on Thomas; then a year later coming up with a dominant game in a Divisional Round win over Carolina that included 11 tackles, an interception return for a touchdown and multiple leaps over the offensive line on field-goal attempts. Whether it was setting the tone with a hit in a Super Bowl win, or in an NFC West rivalry with a crushing sideline hit on 49ers tight end Vernon Davis, Chancellor often embodied the best of Seattle's defenses.

"First off, there's his physical nature on the football field, his physical presence," receiver Doug Baldwin once said of Chancellor. "He kind of brings a swagger to the defense, and to the whole team really. There aren't many people who can go up against Kam and win that battle, so he kind of brings the hammer for the whole team. Then obviously his leadership in the locker room, he's just one of those guys who is down to earth. He can talk to anybody, have a conversation with anybody, cares genuinely about everybody, and he brings everybody together."

Earl Thomas, who started alongside Chancellor for seven seasons, once described his fellow safety by saying, "He definitely sets the tone. He sets the tone. It's something that you can feel. You see he gets up and starts pounding his hands, all that stuff is contagious, and that's when we're at our best, when everybody is doing their own thing and they're bringing it to the group."

Richard Sherman, meanwhile, once noted that Chancellor "plays in a dark place" and "damages people's souls." Yet despite regularly being the baddest man on the field, Chancellor had a huge heart off of it, which is one of the reasons why he won multiple Steve Largent Awards. Chancellor's Kam Cares Foundation helps "equip children from underserved communities in Hampton Roads and Seattle areas with educational, health, and wellness tools and resources to position students for greater academic success." Every Memorial Day Weekend Chancellor hosts his Bam Bam Spring Jam in Norfolk, Va., an event that includes a free cookout. Over the holidays, Chancellor organizes a toy drive to benefit Seattle’s Union Gospel Mission.

Through both his play on the field and his actions off of it, Chancellor made his mark on the Seahawks, the community as a whole, and as Demaryius Thomas, Vernon Davis and so many others can attest, on opposing pass-catchers who had the misfortune of crossing paths with the man known as Bam Bam.