This year, players, coaches, managers and umpires will also have a "42" patch on the sides of their hats and players will wear special Jackie Robinson Day-themed shirts during batting practice.

The Diamondbacks celebrate Jackie Robinson's impact in breaking barriers in baseball and inspiring necessary change in the sport and our nation.

A special piece of Jackie Robinson memorabilia is about to hit auction ... and TMZ Sports has learned it could fetch over $400K!! The 1948 Leaf card is regarded as Robinson's true rookie card ... and ...