The continuing education of Elias Diaz

Elias Diaz crouched behind home plate Thursday afternoon before the Pirates took the field for batting practice. Bench coach Tom Prince and first-base coach Kimera Bartee stood on the mound, Prince firing pitches in the dirt for Diaz to block.

Prince and Bartee huddled, then both whirled and mimed a throwing motion. Only Prince had a ball. Diaz got a fist bump after blocking it.

The 27-year-old catcher made his first opening-day roster as the backup after Chris Stewart blocked him for three seasons. The major league education, begun last season when injuries to Stewart and Francisco Cervelli made Diaz the temporary starter, continued this spring and into the regular season. The degree of…