Primo brings comparable scoring upside to Lonnie Walker IV
Beginning with the player that I'm a bit less concerned about, Lonnie Walker may see the Spurs selecting Primo as a bit of a kick in the butt.
Coming into the league, part of Primo's appeal is his long-term three level scoring upside. While he doesn't have the same level of elite athleticism that Walker brought to the table for the Spurs, Primo is coming in with a more polished jump shot, a crafty finishing ability near the bucket, and good instincts when moving off the ball.
Walker is already serving as the team's backup shooting guard, but that role could easily be taken by Primo in the future if he doesn't make any big strides in his game. If Primo can put some more muscle on his frame, given the tools he already has on defense, he could end up becoming a better defender relatively quickly. His scoring will be his swing skill, though, in terms of whether or not he could realistically compete for Walker's spot on the roster.
Ultimately, though, I don't think the Spurs will necessarily be forced to choose between the two. Walker will still provide the team with a dose of elite athleticism that nobody else can bring, and if he continues to show improvement, he could still have the highest ceiling on the team.
That being said, though, this coming season will be a very important one for Walker. If he fails to show noticeable improvements in his game, he could be on his way to a new team when he becomes a free agent.