The announcement probably comes along with a renegotiation of his contract. Maybe the Yankees halved his contract for next year. Savings = $10 million. Also, Alex will not get the $10 million bonus for hitting home run #700. Next bloated salary to address is CC Sabathia’s.
EDIT: I should say A-ROD is being released on or around the 13th after playing his last game. This is why NYY is on the hook for the 21m$ in 2017. Not officially “retiring.”
MLB contracts are pretty ironclad when it comes to the money. A-Rod and some other big-time players have ‘personal services’ and ‘marketing’ contracts that I don’t think are allowed anymore. That would be a reason to keep him in the organization - to save the Yankees from various kinds of embarrassments.