He went into the locker room for X-rays, which were negative, before returning to the sideline with ice on his right knee.
Phillips went down on an Eagles running play with eight minutes to go in the opening quarter. His knee appeared to bend awkwardly as he attempted to tackle running back LeSean McCoy.
Phillips grabbed at his right knee as he lay on the turf, surrounded by teammates. The fifth-year veteran walked off the field on his own power.
Phillips is no stranger to knee injuries. He underwent microfracture surgery on his left knee in 2009.
Phillips' injury is the latest in a long line of ailments to plague the Giants' secondary this season.
Terrell Thomas had a preseason knee injury that landed him on season-ending injured reserve. Second-year corner Prince Amukamara has dealt with a high ankle sprain that kept him out of the first two games.
And though it's not injury-related, safety Tyler Sash was suspended for the first four weeks of the season for failing a test for performance-enhancing drugs. Sash is expected back this week.
Ian Begley is a regular contributor to ESPNNewYork.com.