1) Nic Claxton
Brooklyn Nets center Nic Claxton is set to become a free agent for the first time in his career and would make for an interesting target. At just 24, he is still developing as a player and is known as a versatile defender who can challenge shots at the rim and effectively guard out on the perimeter.
He doesn't have much range as an offensive player but he is a terrific finisher around the basket. The Spurs could have up to $20 million in cap space, which they could use to sign Claxton outright. Or, they could potentially work out a deal and trade with the Nets, who will need a starting center and may be interested in Collins.
Although Collins has struggled this season, he would give them a more offensive-minded short-term replacement. Meanwhile, Claxton would help boost San Antonio's defense without necessarily hurting their offense. Wembanyama being able to space the floor, in theory, would allow him to share the floor with another non-shooting big man, though the Spurs would also need more shooting from their starting point guard to make that pairing work.
Upgrading at point guard, signing Claxton, and moving on from Collins might not be a lot to ask of the Spurs this summer. Its. It's possible, but perhaps not realistic at the moment.