The Bills made the decision Thursday after Williams' injured meniscus did not respond to almost six weeks of treatment. The starting defensive tackle has not practiced or played since being carted off during the Bills' Oct. 18 loss to the Cincinnati Bengals.
"Looking at it, we at some point, it needed to be done," Williams said. "We just hoped that it could be something that we could put off and I could get through the year and help our team through treatment and hoping that it would respond. How likely that was or not, I don't know, but [we] tried to exhaust all options and cling to as much hope as we can."
Williams, 32, intends to continue his playing career next season.
"I've got no plans to not play anymore," Williams said, adding, "I think the great thing about this game is you're judged on what you do on the field, and when I'm out there, I feel like I do a pretty good job when I'm out there. I think the thing that's not measured is what you have in [your heart] and in [your head], and I've got plenty of that left to give.
"I want to see every goal, every dream I've had since I've been here 10 years ago, I want to see that come true. We've got a great staff and we've got a lot of guys that believe in one another, so I'm gonna give you what I got until I can't. And we'll figure that out together."
A fifth-round pick in 2006, Williams is the Bills' longest-tenured current player and has been named to four Pro Bowls, including in each of the past three seasons.
"Up until this point, I felt pretty good this year. I actually felt healthy, really good," Williams said. "It's just something that it's kind of the price of doing business sometimes. It's just the nature of this league. You got guys who come back and play, so that's what my plan is."