Pay him his 8.5-9m. Its 3.5m more than he gets this year, but the cap is going to go up by 1-2m, and we've got buyouts and other penalties falling off the books.
Every top team has one or more of their best players locked up to contracts into sketchy years, its just what you have to do. And tbh, in 6 years time, when the cap has gone up again a bunch of times, that 9m might not look so bad.