Colorado Rockies Rookie of the Year winners
1 player won the Rookie of the Year in a season with the Colorado Rockies. It is Jason Jennings (2002).
A winner counts for a club when he played for it in the season he won, the Immaculate Grid's rule. Award lists from Wikipedia. Every season since 1876 is on file. A season split between two clubs is filed as one combined line and counts for neither.