Rocky Carroll made his first NCIS appearance in the Season 5 episode “Internal Affairs,” which aired some 14 years ago. He was a recurring cast member in Season 5, before being promoted to the main cast in Season 6.
The role reunited him with Mark Harmon. The two had previously starred together in another CBS hit, the medical drama Chicago Hope. Harmon played rough-around-the-edges orthopedic surgeon Jack McNeil while Carroll portrayed the strait-laced ER doctor Keith Wilkes.
Both joined Chicago Hope in its third season and stayed on for the remainder of the series. Carroll also portrayed veteran CIA agent Carl Reese in CBS’s spy thriller The Agency from 2001-2003, which likely made him the perfect fit to play Director Vance in NCIS.
Source: https://www.distractify.com/p/is-vance-leaving-ncis
