Bridges had six catches for 64 yards and a touchdown for Berlin. He was in camp with the Chicago Bears last year before being released prior to the start of the regular season.
Bridges, whose last year at South Carolina was in 1997, also has spent time in training camp with Minnesota and the Cleveland Browns.
He stands only 5 feet 7, 170 pounds and will wear No. 18 with the Dolphins.
Bridges took the place of fellow wide receiver Damon Savage, who was waived after failing his physical because of a knee injury.