"It's in the second or third rib ... . The cartilage looks like it's cracked in there a little bit," Eagles Coach Andy Reid said. "It's not the bone. It's up high on the sternum."
Reid described Vick's health situation is "day-to-day and week-to-week," and didn't say whether Vick could play against San Francisco Sunday night.
Magnetic resonance imaging Monday revealed the damage.
Vick was scrambling toward the goal line late in the first quarter Sunday when he was crunched by two Washington defenders. He walked off the field on his own but the Eagles went on to lose 17-12.
Vick was 5-of-7 for 49 yards with three rushes for 17 yards before leaving the game.
Reid also said injured running back LeSean McCoy's status for Sunday is unknown. McCoy suffered a fractured rib in the second quarter against Washington. McCoy remained in the game, running for 64 yards on 16 carries and adding 12 receptions for 100 yards.