https://www.catscratchreader.com/2020/1/15/21066845/nfl-carolina-panthers-luke-kuechly-retirement-cap-space-2020-what-does-it-mean
looks like it’s same as a trade. Don’t have to pay any guaranteed money that hasn’t already been paid. Dead cap from bonus amortization hits in year of retirement.
so if Star retired, he’d forfeit his $5m in guaranteed salary, but $5.2m of future bonus amortization would hit this year. So basically a wash cap wise if he retires, but clears cap space in future years.