Hill has served a four-game suspension for violating the NFL's performance-enhancing substance policy.
The Giants placed cornerback Michael Coe on injured reserve to create a roster opening. Coe suffered a hamstring injury earlier in the week in practice.
Also, right guard Chris Snee made the trip to Cincinnati. Snee was listed as questionable for the game with an ankle injury but was active Sunday.
Hill provides the Giants with depth at safety and special teams. Phillips is out with a knee injury and hopes to return against Green Bay after next week's bye.