According to Yahoo Sports! NFL Insider Jason Cole, Cincinnati Bengals offensive guard Jacob Bell has retired from the NFL. Bell signed a one-year deal on April 11, 2012 worth $890,000 with a $65,000 signing bonus. No word if Bell retired due to the team's decision to select Kevin Zeitler in the first round, general love for the game diminishing or something else. It's too early to postulate a theory at this point.
As for the Bengals there are questions.
Zeitler and Wharton are your obvious starters, with Clint Boling and Otis Hudson the most natural backups. However the Bengals have a decent collection of undrafted free agents to check out from now until the end of the preseason, including Trevor Robinson, Mike Ryan and perhaps Ben Bojicic as well as Chris Riley.
Bell, largely projected as a backup, was the second guard signed by the Bengals during free agency this year, behind Travelle Wharton, who is expected to start at left guard. An eight-year veteran selected No. 138 overall during the 2004 NFL draft out of Miami University, Bell played his first four season with the Tennessee Titans before completing his career with a four-year stint with the St. Louis Rams.