[Drstrangelove]

IRL, iirc, some contracts aren't always paid. If a player refuses a trade and it's early in their career (around 3 years), an existing contract can be voided and the player becomes a free agent. So, a player traded to team B (or C), who then refused an assignment to the minors, or refused the trade to team C, might then have his contract voided. In that case, the retention should disappear. In most cases, (once a player has enough years), the contract would still be payable (in full) even if the player was cut by team B or C, regardless of the trades, and team A would still owe part or all of the contract.

For example, I traded a player and retained most of his contract for 2 more years. He then was released and signed as FA in the minors. I still owe that retention next year and the year after. (It stops showing up as salaries and now appears in miscellaneous player expenses.)