In December of 2014, the Rockies acquired Diaz from the Los Angeles Angels in exchange for Josh Rutledge. The trade generated very little fanfare. If anything, it was only notable at the time because it signified that Colorado was committing to DJ LeMahieu at second base.
Diaz entered the Angels system as a catcher, but after two years of struggling to hit at the lowest levels of the minors, he was converted into a relief pitcher. Diaz wasn’t an instant success, but armed with a fastball that could reach 100 MPH, he eventually worked his way through the ranks of the minors, going all the way from High-A to MLB in 2014.