Mets retire Willie Mays' No. 24 as Old-Timers' Day returns
Mets retire Willie Mays' No. 24 as Old-Timers' Day returns
Mets to retire Koosman's number — Queens Daily Eagle
Mets to retire Keith Hernandez's number in 2022
Mets to Retire Jerry Koosman's Jersey - The New York Times
Jerry Koosman: All Time Mets Left Handed Pitcher (Part One: 1967-1972)
New York Mets retire Keith Hernandez No. 17 jersey
Keith Hernandez jersey to be retired by Mets
Humble Jerry Koosman joins Mets hopefully-expanding pantheon with number retirement