The 30-year-old Bowman earned First-Team All-Pro honors four times in his career (2011-13, 2015), as well as three trips to the Pro Bowl (2013-14, 2016).
During his career, Bowman has appeared in 99 games and registered 798 tackles, 14 sacks, five interceptions (returning one for a touchdown), seven forced fumbles, six fumble recoveries and 29 passes defensed. Bowman also led his team in tackles in four of the previous six seasons (2011-13, 2015).
Bowman missed the entire 2014 season after suffering a gruesome leg injury in the 2013 NFC Championship Game loss to the Seattle Seahawks.
He spent seven-plus seasons with San Francisco after being selected by the club with a third-round pick in the 2010 NFL Draft. Bowman was released by the 49ers in October at his request due to reduced playing time before signing with the Raiders.
The Browns are in need of assistance at inside linebacker, given the hamstring injury sustained by Joe Schobert on Sunday.