Dean Demopoulos, Marc Iavaroni and Robert Pack will work under Del Negro when he begins his first season with the team this fall.
Dave Severns was hired as director of player development on Thursday.
Demopoulos spent five seasons as the top assistant with the Portland Trail Blazers, and four seasons with the Seattle SuperSonics after 18 seasons at Temple.
Iavaroni spent last season as an assistant with the Toronto Raptors. He was head coach of the Memphis Grizzlies for two seasons. He's also had assistant coaching stints with Phoenix, Miami and Cleveland. Iavaroni played seven years in the NBA and five years in Europe.
Pack was an assistant with New Orleans last season. He played 13 years in the NBA.
Severns worked with Del Negro the past two seasons in Chicago. Previously, he spent 13 years in player development with Nike.