The Chiefs announced the moves before Wednesday's practice.
Grubbs, a two-time Pro Bowl selection with New Orleans, was acquired by Kansas City prior to this season. He started seven games before the neck problem cropped up, and the Chiefs were hopeful that he would be able to return to the field this season.
In other injury news, outside linebacker Justin Houston is day to day with a hyperextended left knee. Offensive lineman Jeff Allen has an ankle injury, while center Mitch Morse and wide receiver De'Anthony Thomas are undergoing concussion testing.
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