At this point, you have to tell Kawhi that the Laker package sucks and that you won't take on Deng's contract and that the assets are not good enough. Also, you tell him the Clippers don't have what it takes and you won't trade him there. By rejected the Lakers (and probably the Clippers), the Spurs are forcing them to get better assets. I doubt either franchise can do that. The Lakers won't find a taker for Deng without giving up a young talent that it needs to compile an acceptable offer to the Spurs. And the Clippers just don't have the talent or the assets to give the Spurs a lottery type player that makes sense.

So Kawhi has to decide how bad he wants out of S.A. If he feels awkward around the Spurs, then he'll have to be flexible on where he will accept being traded, which opens the door to Boston or Phili. Once that door is open, or somewhere else, then the Spurs can look at acceptable trade packages.

The risk is if Kawhi decides to play the year and become a free agent. Spurs risk losing Kawhi for only salary cap relief (don't have to sign him to a super max contract that would handicap the roster for years). But Kawhi risks a changing market, injuries, and the fact that if he signs as a free agent, he'll make millions less than if he was traded with bird rights. So he has every incentive to be traded. I don't think he can avoid playing out as a free agent if he doesn't sign with the Spurs, so if he goes that route, injury and the market will always be an issue, but at least he can play where he feels comfortable assuming he no longer gets along with his teammates.