This is pretty much simple have some players who retired to unretire and maybe even have them play for a different team than they did in their career or come back when a team is hurting in a position they did play in their career.
I don't know enough about how retiring players works in this game to say one way or the other. From what I've seen, players don't often (ever?) retire "early," and few of the players I have seen retire are necessarily peak performers anymore.
