David Canter, the agent for LB Blake Costanzo, announced Tuesday via his Twitter account that his client has signed with the 49ers.
— David Canter (@davidcanter) June 3, 2014
Costanzo, 30, played for San Francisco a few years ago before he signed a two-year contract with the Bears back in 2012.
Last year, he appeared in all 16 games for Chicago, but was limited to playing just 24 defensive snaps. He actually graded out as one of the best special teams players in the league last season, according to Pro Football Focus.
The 49ers are so deep that it will be hard for him to secure a reserve role on their 53-man roster, even though has been an asset on special teams.