1. Let Lonnie Walker go, trade two 1st round picks
Considering he has a $14.5 million cap hold, it's hard to see Lonnie Walker sticking around if the Spurs are going to poach a big name this summer. His departure would already give the Spurs $27 million in cap space to work with, meaning they'd need to find just $3.5 million in their books for this purpose.
Although shedding their 1st round pick would already free up $6.4 million, that wouldn't be a wise move considering there are plenty of talented guys the Spurs can pick to help their cause. Instead, trading their picks from Boston and Toronto for future picks, valued at $2.98 million and $3.12 million respectively, would be enough to get the job done without sacrificing too much.
2. Let all free agents walk, keep all but one non-guaranteed player
Spurs writer Paul Garcia recently broke down cap space projections for different paths the Spurs can take this offseason. With five free agents and four guys on either a non-guaranteed deal or a partial guarantee, they have the flexibility to free up a decent amount of space if needed.
According to his projections, the Spurs can wind up with roughly $29.1 million if they let free agents Lonnie Walker, Devontae Cacok, Joe Wieskamp, D.J. Stewart Jr, and Robert Woodard II come off the books.
That would still put them slightly short of the $30.5 million needed, so one way to get that extra amount would be to part ways with either Keita Bates-Diop, Tre Jones, or Jock Landale. I'm thinking for someone like Ayton, the Spurs wouldn't hesitate to make that happen.
Finally, there's a way San Antonio could retain Lonnie while also clearing room for Deandre, but it's tricky.