Baseball legalese is a funny thing. If a player under a contract declares retirement, they immediately forfeit the remainders of owed money on the contract. However if a player under a contract declares that they are not physically capable of playing baseball any further, but not actually using the terminology “retirement,” then technically, the team(s) responsible for the contract are still obligated to continue paying their financial obligations.
Player A declares retirement, despite having one year and $12 million dollars left on his contract. His team is absolved of having to pay $12 million dollars, upon finalization of retirement.
Player B holds a press conference to let the world know that he is physically incapable of playing baseball any further. His contract has 4+ years remaining on it, at an estimated annual salary of $24 million dollars, per year. As he has not officially declared himself retired, the contract is legally obligated to continue to be paid out until it expires or retirement is declared.