The Jets placed Barnes (ankle) on injured reserve Monday.
Barnes had been ruled out for the Jets' Week 1 matchup with the 49ers and has since been placed on IR with an ankle injury. The second-year linebacker will be forced to miss at least New York's next four contests. With Barnes and Jimmy Ciarlo (knee) on IR, the Jets have just three healthy outside linebackers on their active roster: Quincy Williams, Sam Eguavoen and Jamien Sherwood.