Campbell returned to practice Tuesday but remains in the concussion protocol, Andrew Walker of the Colts' official site reports.
Campbell entered the protocol after a minor car accident last week. While he was on the field Tuesday, he wore a non-contact jersey, indicating he's still working his way through the five steps to gain clearance. If and when he's healthy, Campbell seems like the top candidate to work with T.Y. Hilton and rookie second-rounder Michael Pittman when the Colts employ three-wide formations.