I agree with others that San Antonio will figure it out and Kawhi will stay but...
if he really does want out we could offer a pretty good package come draft night (or during next season). We could offer a package of expiring contracts, young players, and draft picks for him. In all honesty, we could probably offer one of the better deals in the NBA for him.
Lopez, Holiday, and Asik are $26m in expiring contracts (Asik carries $3m into 2019 season but that's a pretty small amount)
Dunn, Portis, Valentine, Payne, Grant are young players (to audition or cut) if they wanted some prospects back
and we own all of our 1st round picks to sweeten the deal
I'm assuming if San Antonio wanted to dump contracts then they would add Gasol back with Leonard. Pau is owed $17m next year and $16m in 2019 (but only $6.7m guaranteed). SAS is capped out right now, so dumping some contracts seems like a good idea. They have a lot of young guards on their roster, so they might not want Dunn (or LaVine). They might also want to dump Rudy Gay ($9m 2019) or Danny Green ($10m 2019) but I doubt it They are serviceable and would only be making back up money on expiring deals.
__________________________
So something like (draft night deal):
Bulls get:
Kawhi Leonard
Pau Gasol
SAS gets:
Lopez
Asik
Holiday
NOP 2018 1st round pick
Bulls 2019 1st round pick
This gives SAS 2 extra 1st round picks in the next 2 drafts, and about $50m in free cap space going into to 2019-20 season as Gay, Green and Ginobili also expire with Lopez, Holiday and Asik. This is the rebuilding path for them. If they go this route then they probably try to move Aldridge at some point.
_____________________________
Maybe they see something in LaVine (after he signs his extension) that they like and they want to pair him with Patty Mills and Aldridge as their new core:
Bulls get:
Kawhi Leonard
Pau Gasol
SAS gets:
Lopez
LaVine
(one of Portis, Valentine, Payne, or Grant whoever they prefer)
NOP 2018 1st round pick
This gives SAS LaVine as a young gunner, Portis (probably) to audition, an extra 1st round pick, and a serviceable big in Lopez who expires. As a bonus, Aldridge played his best basketball next to Lopez in Portland so he'd be happy.
SAS Roster
PG- Mills/Murray
SG- LaVine/Green/Ginobili
SF- Gay/Anderson
PF- Aldridge/Portis
C- Lopez/Portis
With 2 1st additional rounders to round it out. I actually kind of like that roster for them once they use one of those picks on a young center. That's be a pretty good sell I think.
Our roster would look like this:
PG- Dunn/Payne
SG- Holiday/Nwaba(if retained)
SF- Leonard/Valentine
PF- Markkanen/Vonleh(if retained)
C- Felicio/Asik
Clearly we use our 1st round pick on a Center or try to find one in FA. We could probably use an upgrade at SG too but there are a ton of those on the market this year. Sign Marcus Smart at SG and Deandre Jordan at C in free agency?!? Imagine that defense

jk