The Raptors also interviewed San Antonio Spurs assistant coach Ettore Messina and Lithuanian Basketball League coach Sarunas Jasikevicius for the head coaching job, according to Sports Illustrated.
According to ESPN's Adrian Wojnarowski, Nick Nurse will be the franchises next head coach.
Toronto is now the only National Basketball Association franchise without a head coach.
In 2007, he became the head coach of the Iowa Energy in the then-NBA D-League, and was a coach in that league until 2013 when he became a Raptors assistant.
Armed man 'with a bomb' holds three inside a shop
The hostages are being held in the internal courtyard of the building, which contains a mix of offices and residential apartments. Police would not immediately confirm whether the person holding the hostages was armed or describe the nature of his demands.
Casey was sacked last month and was hired by the Detroit Pistons on Monday.
This past season he is credited with playing a major role in overhauling the team's offence, finding ways to move the ball more and manufacture three-point shot opportunities.
Ujiri called the decision to fire Casey "difficult but necessary" following the Raptors' loss to the Cleveland Cavaliers in the second round, the third time in as many years they've been eliminated at the hands of LeBron James and the Cavs.
Nurse coached in Europe for 11 years starting in 1996. He is the franchise's all-time leader in wins, winning percentage, games coached and playoff games coached (51). "I know where we started".