Brown is entering his age-29 season and was considered one of the top interior offensive linemen on the 2009 free agent market. The Rams signed him to a five-year, $37.5 million contract that February, but Brown was benched last season and released by St. Louis on March 12.
The 49ers have a need at guard, where Brown played early in his career with the Ravens. He can also play center.
Brown was the No. 84 overall player on the PFT Hot 100.