By John Turney
Andrew Luck retired from football at the age of 29. Presumably, it is due to the injuries he's suffered and perhaps the lack of being 100% physically. We will know more in the next few hours and days.
Oddly, Jim Brown and Gale Sayers also retired at age 30 and 29 and both of them were first-ballot Hall of Famers. Brown's last season was played when he was 29.
We'll know in five years.