The Spurs are at 15 on the NBA roster, and RIGHT up against the tax, which they have gone on record as NOT being willing to pay this year. Even if you cut Anderson, I'm not sure if that frees up enough for a league-subsidized vet minimum contract. Anderson is the ONLY non-guaranteed contract that will actually reduce the cap/tax burden, and is a non-essential player. I believe Neal locks into guaranteed mode in January, but he's not really cuttable. If they cut Blair, they're still on the hook for his whole cap/tax figure for the year.
The math just doesn't work, unless we pull a trade that both reduces the tax burden and sends out more players than we take in.