Forward Brad Richardson also went on injured reserve Monday before the Kings blanked Detroit 5-0.
Mitchell missed 14 games over the past five weeks with a broken left wrist after getting injured Nov. 5. The veteran defenseman had five points in his first 13 games with Los Angeles.
Richardson incurred an upper-body injury during last Thursday's victory over Calgary. The grinding forward has seven points in 26 games.
Newly acquired forward Marco Sturm is undergoing medical evaluation to finalize his trade from Boston.