3: Nikola Vucevic
Chicago Bulls center Nikola Vucevic will become a free agent this summer, and the 32-year-old will likely pursue one last big payday. Considering he is in the final season of a four-year, $100M contract, he might expect at least $20M a season. The Spurs reportedly had interest in trading for Vucevic a couple of seasons ago, but that never materialized.
He was later traded to the Bulls from the Orlando Magic in a lopsided deal that Chicago almost certainly regrets. Still, Vucevic is a capable player who could draw interest from several teams this summer. The Bulls can't afford to lose him, but they haven't extended him either, increasing the possibility that he could leave town.
Even then, the Spurs shouldn't consider signing him. There is a possibility the team drafts Wembanyama, which would give them their center of the future. Even if they don't, Collins is a good stopgap. He is seven years younger than Vuc and will make significantly less money next season. Vucevic doesn't fit the team's timeline with younger players on the market.