The team announced Friday it has placed the two players on injured reserve. The Giants did not announce corresponding moves.
Harris has an ankle injury and Smith a knee injury.
Harris has played four games this season, seeing action on 44 defensive snaps and 69 on special teams. He has seven tackles.
Smith has played 10 games with four starts, seeing action on 192 offensive snaps and 66 on special teams. He has three catches for 33 yards.