In 1990, the Griffeys became the first father-son pair to play in the same Major League lineup
Ken Griffey Jr. - Wikipedia
Ken Griffey Jr. Wants to See LeBron and Bronny Play Together (Exclusive)
Ken Griffey Jr. on memorable home runs in his career - Marquee Sports Network
Looking back at some of MLB's best father-son duos – NBC Sports Bay Area & California
On this date: Ken Griffey Sr. and Jr. play in same game for first time
On Aug. 31, 1990, Ken Griffey Jr. and Sr. became the first father-son teammates in MLB history
ESPN - On this date in 1990, Ken Griffey Sr. and Ken
Today in Baseball: The First Father And Son Combo on The Same Team
1991 Mother's Cookies Ken Griffey Jr Ken Griffey Sr
Like Father, Like Son: The Griffeys and other sports family dynasties
Ken Griffey Jr. – Society for American Baseball Research