Costello has agreed to sign a two-way deal with the Spurs, ESPN's Zach Lowe reports.

EDGE Analysis

Costello was a standout during the NBA Las Vegas Summer League earlier this month, pulling down an event-best 12.3 rebounds per game as a member of the Timberwolves' squad. The undrafted 2016 prospect won't be in line for immediate playing time in San Antonio, but the two-way contract allows for Costello to develop in the G-League.