It's why Seattle pursued Williams so much during the offseason.
"I told him the other day, 'I wish at 12 years I could still move like you,' because he moves very well for a guy that is going on 12 years," Avril said. "His pass rush skills for a big man to be moving the way he moves is impressive. I'm definitely going to pick his brain to see if I can steal another five years."
The addition of Williams in June seemed like a smart way for Seattle to add a veteran to its defensive line at a relative bargain. Injuries during training camp Williams' signing more vital.
Williams was used all over the defensive front during the preseason and it's expected to continue Thursday night in the opener against Green Bay.
Williams gives Seattle the chance to go big and play a front of three defensive tackles in run situations, but his quickness off the snap means he can also be used in passing downs. Either way, Williams will be a significant part of the rotation up front.
"Kevin keeps the big guy in there. He's a really good technician. He's a terrific, savvy player," Seattle coach Pete Carroll said. "He allows us to match up against the teams that want to load up against us when we want to get big. He gives us flexibility. He's going to play a lot. He's going to be all throughout it. He and Tony McDaniel and Michael Bennett are going to be moving around in there to play their spots, but he is just a real anchor and he's a great kid. We're lucky to add him to our team."
That rotation Seattle used a season ago usually featured six or seven players. Sometimes it was by downs, sometimes by series or drives. The end result was by the time Seattle got to the Super Bowl, the line wasn't worn down by overuse.
Adding Williams, along with the addition of younger players that saw little playing time last season, provides Seattle enough quality depth to make up for the losses of Chris Clemons, Red Bryant and Clinton McDonald in the offseason.
And his regular season debut for Seattle will come against a familiar face. Williams played Green Bay 22 times in his career with Minnesota and knows just getting pressure on quarterback Aaron Rodgers isn't enough.
"He's definitely a cool cat. Pressure really, really, really doesn't get to him," Williams said. "He still keeps his eyes downfield and he buys time with his legs. On top of him having a big arm you really have to get him when you have a chance to get him on the ground. And if you get around him the main thing is trying to take his eyes from downfield and try and get him on the ground. That's the only way you try and slow him down."
Through his career Williams has lived up to being the No. 9 overall pick in the 2003 draft, becoming a five-time All-Pro selection as one of the more dominant interior linemen in the game with Minnesota. Seattle would seem to be getting him at a bargain of $1.5 million for 2014 after playing 718 defensive snaps last season for the Vikings, according to Football Outsiders. No one on Seattle's defensive line last season — playoffs included — played more than 600 snaps.
"I think it will take time just to pinpoint how we're going to do it but just this week will give us a good starting point, and we'll get to roll guys through there and try and make it work," Williams said.