Two weeks ago the Yankees made the most significant commitment to their on-the-fly rebuild when they shipped Adam Warren (and Brendan Ryan) to the Cubs for Starlin Castro. They gave up a cheap yet proven above-average commodity in Warren for Castro, who is owed $40M or so over the next four years. The other rebuild trades didn’t involve giving up players as good as Warren or taking on that sort of financial commitment.
The Yankees are banking on Castro’s youth and talent, which became expendable for the Cubs. Castro had some pretty good years earlier in his career but has been replacement level in two of the last three seasons, so this is a clear risk for New York.