His baseball cards, especially his rookie cards, have been invaluable and highly sought after by collectors since the late 1980s. Here’s a list of Ken Griffey Jr.’s most valuable cards.

Ken Griffey Jr.'s Most Graded Cards and Their Prices Griffey Junior is a one-of-a-kind, second-generation ball player who appeared to be destined for superstardom from birth.

Though he last played a major league game 15 years ago, Ken Griffey, Jr., remains one of baseball's most beloved--and collected!--players.