Eagles head coach Andy Reid said that Smith's knee swelled up on the team's flight to Miami, and as a result, Smith was inactive for Sunday's 26-10 victory.
The 26-year-old totaled 11 receptions for 124 yards and one touchdown in nine games.
Smith, a Southern California product, played in just nine games a season ago for the New York Giants. He racked up 48 receptions for 529 yards and three touchdowns.
To fill the roster slot, the Birds promoted defensive tackle Cedric Thornton to the active roster. Thornton, out of Southern Arkansas, spent the entire season on the practice squad after initially making the 53-man roster to begin the year.