During padded 11-on-11 drills, Cedric Benson was carted off the field due to a shoulder injury. The injury occured after Urlacher and Brown combined to bring him down on the play.
From what I have been reading Benson being carted off was more of a safety precaution, it doesn't seem like the hits were in the shoulder area.
Still it does make the running back situation interesting. With Thomas Jones already out for at least another week 3rd stringer Adrian Peterson will see plenty of time with the first team.
On an off handed note, Grossman must be all smiles, for once it isn't him going down.