Rudy Gay's play this season proved to a mixed bag. He managed to stay relatively healthy and played well down the stretch, though he struggled for long stretches of the season too. Gay, at 34, simply doesn't fit the Spurs' increasingly young roster and would likely provide diminishing returns if he was re-signed.
For those reasons, San Antonio should look to move on from Gay. Luka Samanic, the Spurs' 2019 1st -round pick, is an option. While still a work in progress, Luka has shown enough to warrant consistent minutes and should replace Rudy as the backup power forward next season.
Quinndary Weatherspoon has shown flashes during his short career. He's a good defender and a solid passer, but he hasn't shown that he can be a capable offensive player at the next level.
Quinndary could improve, however. He'll turn 25 in the offseason, suggesting that he's close to his ceiling as a player. Still, Weatherspoon hasn't quite shown enough to warrant an NBA contract with the Spurs.
Cutting ties with all of their free agents could be a drastic move considering the Spurs value continuity. That said, the Spurs should strongly consider making such drastic moves in order to reshape the roster around their young core and get the team back on track.