The injury happened last Sunday while he was catching a touchdown pass.
The Bears aren't sure at this point how serious the injury is or how much time Jeffery will miss. They hope receiver Earl Bennett can return next week to help soften the blow of the loss of Jeffery.
On Tuesday the Bears also signed receiver Kamar Aiken to their practice squad. Aiken played two games with Buffalo last season. He was on their practice squad part of this season.