Back in 2011, Topps released their Lineage card line. It was a brand new design that had inserts that paid homage to series of years gone by. One of the inserts was 1975 minis. The Pirates had three active players get the 75 mini treatment Andrew McCutchen, Neil Walker, and Pedro Alvarez. To this day, I've rarely seen them pop up for sale. After 2 years, I finally have added the Pedro Alvarez to my collection.
If you see the Neil Walker or Andrew McCutchen minis pop up, please let me know.