After signing Russell Okung to a big contract at the start of free agency, this is a move that should surprise no one.
The move will create $3.25M in dead money this year, but will free up $4.875M in cap space overall. The timing of the move is what is interesting here.
The Chargers did not have to release Dunlap for another few days before a roster bonus was due. Which means the Chargers are either being nice and giving him more time in Free Agency, or more likely, they have their eye on someone and are close to making another Free agent signing.