Two words on why the Yankees must seriously consider trading Aroldis Chapman and Andrew Miller:
Mariano Rivera.
Rivera was a once-in-a-lifetime player, a difference maker on a dynasty and seemingly irreplaceable. Except the Yankees have replaced him four times, spectacularly: Rafael Soriano in 2012, David Robertson in 2014, Miller in 2015 and Chapman in 2016.
What made Rivera, Rivera is that no reliever in history was so brilliant year after year for as long as he was plus he is arguably the greatest postseason performer in history. No single player is going to do that any time soon, if ever again.