A knowledgeable source confirmed to ProFootballTalk.com that Bell is leaving the game. The source told the website that Bell, who's 31, no longer has the desire to play football.
Bell later told the St. Louis Post-Dispatch that he decided to retire because he feared for his long-term health in the wake of so many stories about the effects of concussions and other injuries, including the recent suicide of Junior Seau.
The Bengals took guard Kevin Zeitler from Wisconsin last month with the 27th overall pick in the 2012 NFL Draft. They also claimed guard Chris Riley off waivers from the Tampa Bay Buccaneers on Tuesday.