Sean Marks, the former San Antonio center who spent the past two seasons working in the team's front office, will move to the Spurs bench for 2013-14 to complete coach Gregg Popovich's assistant coaching staff, NBA.com has learned. Marks, 38, worked under Spurs president R.C. Buford and assistant general manager Scott Layden as director of basketball operations last season and also served as GM of the D-League Austin Toros. He moves into the vacancy opened by longtime assistant Brett Brown's move to Philadelphia as the 76ers head coach and joins Jim Boylen and Ime Udoka on the game-night bench. Boylen was hired off Indiana's staff in late June to replace Mike Budenholzer, who was hired as the Atlanta Hawks' new head coach.