Jon Lester announces retirement after 16 seasons, three World Series titles - ESPN
Jon Lester, former Cubs, Red Sox pitcher, announces retirement
Former St. Louis Cardinals pitcher Jon Lester decides to retire
Cubs' Jon Lester goes for 13th straight 30-start season - Chicago Sun-Times
Jon Lester retires
Longtime Red Sox and Cubs ace Jon Lester announces retirement
Is Jon Lester a Hall of Famer? - Last Word On Baseball
Former Oakland A's pitcher Jon Lester retires
Jon Lester retires
September 20, 2021: Jon Lester earns 200th and final career win – Society for American Baseball Research