Harbor sustained a back contusion on Thursday night against the Bengals.
The third-year tight end out of Missouri State finishes the season with 25 receptions for 188 yards and a pair of touchdowns. He was the primary tight end against Cincinnati as Brent Celek sat out with a concussion, and caught three passes for 30 yards.
Celek has been cleared to return and is expected to play against the Redskins Sunday. In his absence the Eagles activated Emil Igwenagu, who will likely get some playing time against Washington now that Harbor is out.