The linebacking corps of the Chicago Bears took a hit this morning when Nick Roach signed with the Oakland Raiders. Roach was the starting strong side linebacker, and sometime middle linebacker in Chicago, and was signed away to man the middle in Oakland.

The #Raiders signed Nick Roach to be the starting middle linebacker.

— Sean Jensen (@seankjensen) March 15, 2013

His departure, and Geno Hayes signing with the Jacksonville Jaguars, leaves the Bears with a starting unit of Pro Bowler Lance Briggs at the weak side (Yay!), special teamer Blake Costanzo in the middle (uh-oh...), and untested J.T. Thomas at the Sam (Really?).

MORE: Chicago Bears 2013 Roster Turnover: Linebacker

Roach made $2.815 million last year with the Bears, and reports have his new multi-year deal worth between $3 to $4 million annually. The 'up against the cap' Bears couldn't afford to bring Roach back, but his departure could increase the leverage for free agent Brian Urlacher.

MORE: 2013 NFL Free Agency: Brian Urlacher draws interest from the Vikings

Then again, the Bears still have Shea McClellin on the roster as a potential LB replacement...