I'm asking specifically about Pablo Sandoval, who signed a five year contract with Boston Red Sox, and is now owed $18 million each for 2018 and 2019, plus the balance of his 2017 salary. He was designated for assignment because 1) he had become a "replacement" player, and 2) he was being paid way too much for a level of performance that a "minimum wage" player called up from the minors could match or exceed.
The San Francisco Giants may now want Sandoval back, perhaps on a "trial" basis. Will they have to pick up his expensive contract to rehire him? Can they pay him what they think he's worth and have Boston pick up the difference? Or can they pick up the full contract and dump it back on Boston if they DFA Sandoval themselves?
Have others in the past elected to play again when (in Sandoval's case) they could collect over $40 million (or some lower amount) over several years while not playing?
What has happened in these types of situations?