The 50-year-old Nurse is known for his offensive skills as a coach, winning the D-League championship in 2010-11 and 2012-13 before joining the Raptors.
The short version of that: Hiring internally is unsexy, but most signals point to Nurse being a legitimately good candidate as an National Basketball Association head coach.
But the team was again bounced from the playoffs by LeBron James and the Cleveland Cavaliers, and Casey was let go shortly after.
Thoughts on Nurse as the next head coach?
Nurse has spent the past five seasons as an assistant coach with the Raptors under Casey. He won D-League Coach of the Year in 2011. Wojnarowski reports that Nurse accepted the job on Tuesday morning.
Mike Budenholzer, former Atlanta Hawks head coach and Spurs assistant, was also seen as a front-runner before being hired by Milwaukee.
One month into their coaching search, Masai Ujiri and the Toronto Raptors may have neared a decision on who will be the team's next head coach.