Brian Stull of 101 ESPN in St. Louis reports St. Louis Rams guard Jacob Bell will miss four-to-six weeks after undergoing arthroscopic knee surgery this morning.

Bell's estimated recovery time means the 29-year old left guard will likely miss all 14 of the Rams' "Organized Team Activity" sessions, which got underway. Bell will also miss the three-day mini-camp the Rams have scheduled for June 10-12.

A fifth-round pick (138th overall) out of Miami University (Ohio) by the Tennessee Titans, Bell has started 72 of 81 games during his six-year NFL career. Bell signed a six-year, $36 million dollar contract which included $13 million dollars in guaranteed money with the Rams as a free agent in 2008.

The 6-5, 300-pound Bell has started 13 for the Rams in each of the past two seasons, missing the final three games of last season with a hamstring injury.