44th pick: Tristan Vukcevic
The Spurs also have an extra second-round pick thanks to the Jakob Poeltl trade with the Toronto Raptors. While the team could potentially package the 45th and 33rd picks to try and move up to acquire a second first-rounder, Bleacher Report has them selecting Tristan Vukčević. Vukčević is a 6'10" power forward from Serbia who has shown an ability to score both inside the paint and beyond the arc.
At barely 20 years old, he could be worth taking a flyer on midway through the second round, and a newly created third two-way roster spot would allow San Antonio to draft and develop him in Austin. That new wrinkle in the collective bargaining agreement could encourage the Spurs to take more risks in the second round, and Vukčević could be one of them.
Despite this particular mock draft not having the Spurs select first, it would be a decent draft scenario for the team. Fortunately, their draft positioning isn't set in stone, and they will hopefully pick first or second in both the first and second rounds.