At face value, right now the Spurs have 10 occupied slots belonging to De'Aaron Fox, Devin Vassell, Keldon Johnson, Stephon Castle, Julian Champagnie, Victor Wembanyama, Luke Kornet, Dylan Harper, Carter Bryant, and Harrison Barnes.
An NBA team can carry a maximum of 15 players on standard guaranteed contracts during the regular season.
As of right now, there are five open slots and we can expect that one or two of those will be consumed by signing incoming rookies to their standard first-year scales.
This leaves the front office with 3 strictly open standard roster spots to target outside free agents.
Keep in mind that trades might also be a wildcard.