Sullivan was cut from the Panthers' practice squad Thursday, Darin Gantt of the team's official site reports.
Sullivan joined Carolina's practice squad Sept. 30 but never received an elevation to the active roster. The 27-year-old will now have to work to find another opportunity, but he could be a candidate to return if Ian Thomas (calf) and Tommy Tremble (concussion) cannot suit up in Week 6 against the Falcons.