The Blues announced on Monday the former Chiefs assistant would be part of their coaching team alongside head coach Tana Umaga and Leon MacDonald, who were confirmed in their roles in May.
Coventry, who won two Super Rugby titles as an assistant coach at the Chiefs, guided North Harbour to the semifinals of last year's National Provincial Championship (NPC) and has had close recent involvement with the Blues as coach of their development team.
Blues chief executive Michael Redman said the club was impressed with Coventry's credentials.
