Griffey hit a double in his first at - bat .
Ken Griffey , Jr. made his major league baseball debut on opening day , April 3 , against the defending league champion Oakland Athletics .
Ken Griffey , Jr. hit a double in Ken Griffey , Jr. 's first at - bat .
Ken Griffey , Jr. made his major league baseball debut on opening day , April 3 , against the defending league champion Oakland Athletics .