Gleyber Torres was the key piece acquired last season for Aroldis Chapman, a deal that was essential in bringing the Cubs their first World Series in over 100 years. Torres showed immediate dividends by becoming the youngest player ever to win the Arizona Fall League Most Valuable Player Award (side note, Greg Bird also won this award in 2014).
Torres is interesting because he is a shortstop with good hands, a strong arm, and off-the-charts hitting ability. His ability to drive the ball to right field should help him in Yankee stadium and he is versatile enough to play second or even third (though management wants to keep him in the middle of the field). He also is said to have a great makeup, especially for a 20 year old.
How soon could he be in the Bronx? The most likely scenario is 2018, but if he dominates AA and AAA there is a chance the Yankees could bring him up in 2017. Would he be a candidate should something happen to Didi or Castro? Time will tell, but he has all of the tools and his arrival in the Bronx appears to be inevitable.