5. Nikola Vucevic
At least on the surface, it may be a bit of a pipe dream for the Spurs to target (and land) Nikola Vucevic in free agency. But I do believe that he would be a great mentor/veteran the Spurs could turn to in an attempt to help Victor Wembanyama as he makes his transition to the NBA.
Of course, the big question is whether Vucevic is at the point in his career where he's ready to take on such a role. He'll be 33 years old by the time next season begins but has not played off the bench on a consistent basis since his rookie season in the NBA. There is a very real possibility that he'd much rather be a starter next season and/or play for a contender; the Spurs would not be able to give him that opportunity (assuming the plan is to start Wemby from the opening tip).
But perhaps he would be attracted to playing a small role in Wemby's future. Vucevic could be viewed as somewhat of a dream scenario for the Spurs this summer as they search for potential veteran big men that could help be a springboard for the Wemby-era in San Antonio.