The San Antonio Spurs initially seemed like a perfect trade partner in a Giannis Antetokounmpo deal, but if their two up-and-coming guards are off the table, no thanks. Per NBA insider Jake Fischer (subscription required), there is "little indication" that the Spurs are willing to trade Stephon Castle or Dylan Harper in any deal.
Bucks shouldn't even negotiate with Spurs if rumor holds true
If the Spurs make it clear that Harper AND Castle are both off the table, the Bucks should no longer even pick up the phone. In any trade, one of Milwaukee's biggest asks for their generational star will be a young, rising player who can be their next building block.