Why did Andrew Luck retire? Tragic story of Peyton Manning's

Andrew Luck was the perfect quarterback. He had all the physical gifts and intangibles you'd want in a signal caller, and he was putting up the numbers to back it. And yet, he tragically retired at 29 years old.

Peyton Manning Helps Colts Kick Off 35th Season In Indianapolis

Ex-Colts QB Andrew Luck enjoying quiet retirement life

FMIA: Andrew Luck, the Colts and the Retirement That Rocked NFL's World - NBC Sports

Andrew Luck opens up about what led to him retiring from the NFL - Sports Illustrated All Cardinal News, Analysis and More

Peyton Manning's father believes his son and Andrew Luck could play together

Why did Andrew Luck retire? Tragic story of Peyton Manning's successor reveals flaws in Colts' organization - The SportsRush

Indianapolis Colts quarterback Andrew Luck announces retirement from NFL - The Washington Post

NFL: Indianapolis Colts star Andrew Luck retires after 'cycle of injury pain'

Andrew Luck: Why Peyton Manning's Departure from the Indianapolis Colts Is Bad for Him

Kiszla: Peyton Manning, Andrew Luck follow in footsteps of their fathers – The Denver Post