I wonder if the team would consider stretching Tony next summer. I can see them not trading him out of respect, but they can't keep him on the roster if he doesn't get better. So the compromise seems to be to either trade him to a team he wants to play for (probably not that hard) who wants him (probably not easy at all) and failing that to release him and hope he signs a decent deal somewhere else that will allow them to claim set-off relief in 2018-2019. That would leave the Spurs with about $13 Million in cap space. That doesn't seem like a lot, but it also gives you Mills' cap hold, so you could probably bring back the whole bench minus Manu and Bertans, Murray and Forbes in addition to the non-Parker starters. The issues are that 1) They are missing a second PG and have almost no means of getting one and 2) If you factor in Mills and Simmons getting deals far in excess of their holds, rookie players getting that extra 20 percent and the room exception, the team is threatening the tax hard core.
This would be the roster:
PG: Mills, Murray, Forbes
SG: Green, Simmons, ...
SF: Leonard, Anderson, ...
PF: Aldridge, Lee, Bertans
C: Gasol, Dedmon, ...
Would probably be ideal to draft a guard in June and bring over Milutinov to balance out the roster.
Or they could keep Parker, and stay over the cap. That would mean that they'd have to hope Dedmon would take the MLE, but that's not a horrible be with it being projected at $8.7 Million. That would be $37M/4 at its max, which is insane. Then you could give Patty whatever he wants to be the starter and tell Lee it's min, LLE or GTFO. Also could keep Manu for whatever deal, but that's not ideal either.
PG: Mills, Parker, Murray
SG: Green, Simmons, Forbes
SF: Leonard, Anderson, ...
PF: Aldridge, Bertans, ...
C: Gasol, Dedmon, Milutinov
With the pick, the LLE (like $7M/2) and min deals to fill the other two spots.