(Undated)  --  The Celtics are planning to hire Nets assistant coach Ime Udoka as their new head coach.  Udoka will replace Brad Stevens, who recently took over as Boston's president of basketball operations.  The coach joins the Celtics after one season as an assistant on Steve Nash's staff in Brooklyn.  He previously spent seven seasons as an assistant with the Spurs and one with the 76ers, winning a NBA championship in 2014.  Udoka also played in the NBA from 2004-to-2011.