The Bears already knew linebacker Sam Acho was done for the year, but they waited a week to use his roster spot.
The team announced that Acho was placed on IR today, so they could sign offensive lineman Bryan Witzmann.
Acho suffered a torn pectoral muscle last week, so this was an expected move.
Acho signed a new two-year deal with the Bears this offseason, after a solid four-year ru there. The 30-year-old began his career with the Cardinals.