Chicago Cubs new starting pitcher Jon Lester poses for photos with

Former Cubs pitcher Jon Lester, part of team's World Series core, announces his retirement - Chicago Sun-Times

Chicago Cubs send southpaw Jon Lester to the mound in Tuesday's series finale

Red Sox Trade Lester, Gomes To A's

Chicago Cubs General Manager Jed Hoyer (L) smiles as new starting pitcher Jon Lester tries on his hat at a news conference in Chicago on December 15, 2014. Lester agreed to a

Jon Lester, LHP, Chicago Cubs,Pitching Mechanics at 200 FPS

MLB Rumors: Jon Lester has retired - Lone Star Ball

Chicago Cubs new starting pitcher Jon Lester poses for photos with his wife Farrah and sons Walker, 1, (L) and Hudson, 4, after his introductory news conference in Chicago on December 15

Cubs ace Jon Lester on Father's Day

360 Jon Lester Photo Day Photos & High Res Pictures - Getty Images