The Raiders placed Koonce (knee) on injured reserve Saturday.
Koonce popped up on the injury report Thursday with a knee injury. He was ruled out for the Raiders' regular-season opener against the Chargers, and the 2021 third-round pick will now be forced to miss at least the first four games of the season. With Koonce sidelined, Janarius Robinson is set to see an increased role on the Raiders' defensive front alongside Maxx Crosby, John Jenkins and Christian Wilkins.