As he heads into free agency, Williams is seeking help from a former star.
Seymour told ESPN's Mike Reiss that he's working with Williams on the mental-approach first and foremost.
"I've worked with guys in the past -- not so much on-the-field work, but just mentality, mindset," the 40-year-old Seymour said. "Here's the thing: In my mind, anybody can be good if they have a certain amount of talent. But what I try to give guys is the mindset of what it takes to be great, and to be great consistently. To develop a mentality over the course of your career. I'd say Leonard has all the tools for what it takes to be great."
The No. 6 overall pick in 2001 by Bill Belichick, Seymour knows the high expectations that can undermine a young player's development.
"I respect the hard work of guys that come in the fourth, fifth, sixth, seventh round, but it's different when you are the guy and have to perform at that level, basically with a target on your back the whole time and live up to that. And exceed expectations," he said.
"I've been telling him, it's really about competition. Competing. And hanging around and being around people who have the same mindset, being in that environment all the time. It helps in terms of what you're trying to accomplish."
In five years, Williams has been solid but unspectacular, generating 17.5 sacks, 266 tackles and 254 total QB pressures. Williams hopes working with Seymour can help unlock the talent to improve his play down the line.