In 2014, Sloyan guest starred in four television series including, Castle, Parks and Recreation, Hawaii Five-0 and Rizzoli & Isles. She began a recurring role in the ShondaLand produced show Grey's Anatomy as Dr. Penelope Blake. She first appeared in the eleventh season highly critical episode "How to Save a Life", which included the death of lead character, Derek Shepherd, played by Patrick Dempsey who had starred on the series since the beginning. She appeared again in the twelfth season, including the show's 250th episode "Guess Who's Coming to Dinner" which was mostly focused on Sloyan's character.