Koo (back) was limited at practice Thursday, Scott Bair of the Falcons' official site reports.
One day removed from sitting out due to a back injury, Koo was back on the field with a cap on his reps, giving him just one more chance to get back to full before the Falcons potentially give him a designation for Sunday's game against the Saints. Atlanta signed kicker Matthew Wright to its practice squad Thursday as insurance in the even Koo is unable to go this weekend.