Both new members of the ensemble will appear in the season premiere in September.
"Warren will play Kalinda's manipulative ex-husband, to whom she has an attraction that she finds impossible to ignore. Tierney will play a self-made millionaire who has become the doyenne of Chicago Democratic politics," a synopsis said.
Archie Panjabi plays Kalinda in the legal drama, which also stars Emmy and Golden Globe Award-winner Julianna Margulies.
Swim Week Miami Beach 2014 [PHOTOS]