Glenn had battled an ankle injury all season and became the 14th Saints player to be put on the IR list this season.
Glenn, a 15-year veteran, appeared in only four games this year with eight tackles and one pass deflection. He originally injured his ankle in Week 2 and re-injured it three weeks ago.
The Saints activated defensive end Josh Savage from the practice squad. Savage, who has played sparingly in his two games this season, will likely replace Jeff Charleston as the team's No. 3 defensive end this week.
Charleston missed practice Thursday with a foot injury.