At age 26, Ravens' John Urschel retires from NFL to pursue PhD in math at MIT - The Washington Post
Football's moment of truth
Concerned with long-term damage from head injuries, Ravens offensive lineman John Urschel retires
Why A 26-Year-Old Baltimore Ravens Lineman Is Leaving The NFL
John Urschel retires from the NFL at age 26
Ravens OL John Urschel Retires After CTE Study, Continues Pursuit of MIT Ph.D., News, Scores, Highlights, Stats, and Rumors
Rob Gronkowski apparently is an extremely frugal person and is retiring at 29. : r/Frugal
MIT's John Urschel On The NFL, Concussions And Settlers Of Catan
Baltimore Ravens Offensive Lineman John Urschel Retires From NFL At 26
John Urschel didn't tell Ravens he was a full-time Ph.D. student at MIT while in the NFL
NFL, NIH End Partnership For Concussion Research With $16M Unspent : The Two-Way : NPR
Sullivan: Brain damage remains football's greatest foe
John Urschel: From NFL Lineman To MIT Math Professor
John Urschel, Ravens lineman, retiring from football at 26
John Urschel retires from the NFL at age 26