Seattle Mariners star Ken Griffey Jr. announced his retirement from professional baseball Wednesday, after 630 career home runs and two months into his 22nd season. Griffey, 40 years old, inked his first professional contract in 1987 for the Mariners, and spent much of his career in Seattle, minus a decade spent mid-career in Cincinnati and Chicago. The player said in a statement that the decision was difficult and that he’s “extremely thankful” for his long career and the friendships made during it. His father, Ken Griffey Sr., was a star player for the Cincinnati Reds, and the father and son played together in 1991, the first pair to do so. Among his many honors, Griffey appeared on an episode of The Simpsons.