A heavy part of their 2015 success is contingent on the health and, therefore, effectiveness of Masahiro Tanaka. The narrative rightfully flowed as something like this: Whichever way their Japanese ace goes, so too shall the Bombers.
The Yankees are now in full-blown "hope that isn’t the case" mode after Tanaka had to be shuffled to his dark place, the 15-day disabled list. And those 15 days will not be his maximum time spent there. Per Jack Curry of the Yes Network, Tanaka apparently suffered a "small forearm strain":
Tanaka's MRI showed a small forearm strain so he will be placed on the 15-day DL.