The concussion against the Bengals was the third concussion Robinson has suffered this year since training camp, and was the second straight week that Robinson has been diagnosed with one. Robinson was also diagnosed with a concussion against the Indianapolis Colts in Week 3.
Along with Robinson, starting outside linebacker Daryl Smith also missed practice for the second day in a row due to a groin injury.
Center Brad Meester and defensive tackle Tyson Alualu were both full participants at practice Thursday after each missed practice for non-injury related reasons.
Defensive end George Selvie was limited in practice for the second day in a row with a knee injury. Selvie has missed all of the season so far as he recovers from a sprained knee suffered in training camp.