The Jets placed Cooper (ankle) on injured reserve Saturday, Amanda Vogt of the team's official site reports.
Cooper thus will miss at least the next four games after he suffered a sprained ankle in his pro debut this past Sunday in Tennessee. His next chance for game action will be a Week 6 road matchup with the Patriots on Sunday, Oct. 18, and in the meantime, the Jets will operate with a receiving corps composed of Garrett Wilson, Adonai Mitchell, Isaiah Williams and Arian Smith.