Brooks did not have his contract renewed with the Wizards following the season and an appearance in the first-round of the playoffs.
Meanwhile, the Blazers mutually parted ways with Terry Stotts and have been looking for an assistant with experience for Billups, entering his first season as a head coach after one year as an assistant with the Clippers.
Brooks was an assistant before — with the Nuggets, Kings and SuperSonics/Thunder. Along with the Wizards, he has served as head coach of the Thunder, guiding them to the Finals in 2012.
Brooks compiled a 183-207 record with the Wizards, and is 521-414 in 12 seasons overall.
The Blazers were also reportedly considering Vinny Del Negro and Lionel Hollins for lead assistant roles. But Brooks is “a significant addition for Billups as he builds his new staff,” Wojnarowski wrote.
Portland has made the playoffs in eight straight seasons.