Andrew Luck’s sudden retirement from the N.F.L. sent shock waves across the social media and sports talk radio landscape, with many athletes empathizing with the former No. 1 pick of the Indianapolis Colts for putting his physical and emotional well-being ahead of future earnings and on-field accolades.

But the unexpected exit of the franchise quarterback at the age of 29 prompted a debate over Luck’s grit in the face of a laundry list of injuries that have kept him sidelined for one full season and half of another during his six years in the league.

Luck, who has grappled with a lacerated kidney, a concussion, a torn labrum in his shoulder and other injuries, most recently had been dealing with an ankle problem.

“Retiring cause rehabbing is ‘too hard’ is the most millennial thing ever,” Doug Gottlieb, a Fox Sports Radio host and former college basketball player, said on Twitter on Saturday.