When I first heard this, my initial reaction was: Will he stay retired?
Williams stunned the NFL with an early retirement in 2004. But he was back in July 2005.
He talked retirement before the 2009 season, saying he wanted to play two more seasons before calling it quits. But he played with Baltimore in 2011.
Williams, 34, even spoke about his intentions about playing next season for the Ravens after the AFC championship game loss at New England.
“My body feels good and I know I’m going to train hard and so I’m excited about next year,” Williams said last month, via the team's website. “I’ve grown a lot, kind of falling into a new role and a new city and a new organization, and I’ve gotten better. And like everyone else, I feel like I have something to build on for next year.”
So, what changed?
After the news broke about his retirement today, Williams addressed it in a cryptic Twitter message: "Thank you all, but this ain't it. I'm gonna do something really special. 'Be you and change the world.'"
If Williams does follow through with his retirement, it will be a big loss for the Ravens even though Williams isn't the same powerful running back from a few years ago.
What the Ravens lose isn't the stats that Williams produced last year. He rushed for a career-low 444 yards and scored two touchdowns.
What the Ravens lose is a reliable insurance policy for running back Ray Rice. If Rice went down for any significant amount of time, Baltimore didn't have to worry about handing the ball to Williams, one of 26 players in NFL history to rush for 10,000 yards.
To be honest, Williams was underused in his first season with the Ravens. He averaged less than seven carries per game and caught 13 passes, but it was hard to get him onto the field because it meant taking Rice off of it.
The Ravens signed Williams last year to a two-year contract to replace Willis McGahee, so it appears that their preference is to have an experienced backup. Baltimore's third-string running back Anthony Allen, a seventh-round pick last year, looked like he would need another year before becoming the team's primary backup.
This means the Ravens will be searching for a second-tier running back in free agency.