Linebacker Blake Costanzo, a popular 49ers special-teams standout in 2011, is back with the club, according to agent David Canter.
Costanzo, 30, a seven-year NFL veteran, played with the Cleveland Browns in 2009 and 2010 under special teams coordinator Brad Seely, who brought Costanzo with him to the 49ers in 2011.
Costanzo signed a two-year contract with the Chicago Bears in 2012.
In his second tour with the 49ers, Costanzo will face stiff competition to earn a roster with with a roster that includes several veteran special-teams players, including C.J. Spillman, Craig Dahl, Bubba Ventrone and Kassim Osgood.