Atlanta placed Koo on injured reserve Wednesday, after the kicker was believed to have aggravated a right hip injury in Monday's 15-9 win over the Raiders, Terrin Waack of the Falcons' official site reports.
Koo hadn't been included on the Falcons' Week 15 injury report before playing in Las Vegas, though Atlanta had listed him on its report back in Week 13 due to the hip issue. He converted an extra-point attempt and field goals from 40 and 48 yards Monday before misfiring on his fourth and final kick of the night, a 42-yard try with 5:31 remaining in the fourth quarter. Koo may have aggravated the hip issue on that attempt, and with his move to injured reserve, he'll have to miss the final three games of the regular season plus the wild-card round of the playoffs, should Atlanta clinch a playoff berth. The Falcons signed Riley Patterson off the Browns' practice squad to replace Koo as their kicker beginning with Sunday's game against the Giants.