Koo previously played in the NFL as a member of the Los Angeles Chargers in 2017, where he was 3-of-6 on his field goal attempts. He was recently a member of the Atlanta Legends, a team in the Alliance of American Football, which has since stopped operation. With the Legends, Koo was a perfect 14-for-14 on his field goal attempts. He signed with the New England Patriots' practice squad in September, but was released on Oct. 15.
Koo was a third-team All-American for the Eagles in 2016 and was a finalist for the Lou Groza Award which is given to the nation's top kicker. The other two finalists that season, Daniel Carlson (Raiders) and Zane Gonzalez (Cardinals), are both kicking in the NFL as well.
The Ridgewood, New Jersey, native went 19-for-20 on field goals his senior season.
Koo becomes the second former Eagle player active in the league this season, joining Matt Breida of the San Francisco 49ers. The two teams will meet in Week 15 on the west coast. J.J. Wilcox (Falcons) and Jerick McKinnon (49ers) are both on injured reserve and out for the season. Ukeme Eligwe is on the New York Jets' practice squad.