How prospect supply will shape Yankees’ trade deadline

Yankees general manager Brian Cashman almost never concedes big-time prospects at the trade deadline.Johnny Cueto, Cole Hamels and Justin Upton are viewed as the holy trinity of the upcoming trade market. They currently project as the most talented players almost certain to be dealt to contenders before 4 p.m. on July 31.

Big-game hunting history will be cited as why the Yankees should not be counted out on any of the major pieces.

But if history is our guide, the Yankees only have made one trade in the past 10 Julys that involved them giving up an elite prospect – and that trade did not even get consummated. In early July 2010, the Yankees agreed to include Jesus Montero as the key piece of…