Donnie Wahlberg did not permanently leave Rizzoli & Isles for Blue Bloods in the sense of abandoning one show to join the other full time; rather, his availability changed because Blue Bloods was already a long-running commitment when Rizzoli & Isles was in development and renewal discussions. He remained a series regular on Blue Bloods throughout Rizzoli & Isles’ run and returned for its final season in 2016. This status clarification explains Wahlberg’s scheduling constraints, the shows’ overlapping production windows, and how network renewals shaped his television workload.
