An announcement is expected next week.
Turgeon could not be reached for comment.
Haynes, who was on John Beilein’s staff for the past two seasons, will replace Kevin Broadus, who left in late April to become the head coach at Morgan State.
The 35-year-old Haynes, a former Mid-American Conference Player of the Year and honorable All-American at Kent State who later played professionally in Europe, was one of two Beilein assistants not retained by new coach Juwan Howard.
Haynes was reportedly instrumental in the development of guards Zavier Simpson and Jordan Poole. Simpson was named to the All-Big Ten second team and All-Defensive team last season.
Beilein also allowed Haynes to call some of the offensive sets used by the Wolverines, considered among the most efficient offensive teams in the country.
The anticipated hiring of Haynes comes after a prolonged search where Turgeon interviewed a number of candidates, including former Maryland point guard Duane Simpkins, now on the George Mason men’s basketball staff.
Haynes has a different kind of profile from many of the assistants Turgeon previously had on his staff over the past eight years at Maryland in that he is known more for player development than recruiting.
Broadus made his impact more on the recruiting end during his two seasons in College Park, having helped bring in all five players in the 2019 class — including 7-foot-2 center Chol Marial — as well as four of the six players who remain from the 2018 class.