I think he will be bought out or danny will use the stretch provision. It could be an ok situation for danny in that if he drafts one of the many talented sfs, they can come off the bench and compete with green , making him a better player or increase his trade value
I would be shocked if this happens before his final season, unless it coincides with other moves to get a lot of cap space this summer (which is unlikely). All that would do is make the team worse, take away a future asset (his contract will be very tradable after next season), and will take away cap space for 5 years into the future.
If it's one year, then the stretch provison would be for 3 years per the NBA Salary Cap FAQ:
"If the contract or extension was signed under the current CBA, the remaining guaranteed salary is paid over twice the number of remaining years, plus one, per the Stretch provision. ... If the player's salary payments are spread-out using the Stretch provision, the team may elect to stretch the salary cap charge to match. For example, if two seasons remain on the player's contract when he is waived, and the payment is spread-out over five years per the Stretch provision, then the team may elect to spread-out the salary cap hit over those same five years."
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In any case, if they stretched GW's 1 year for $10M over three years, they would save themselves $6.67M on the cap for 2015, which is a lot.