, known as the 's ironman at the quarterback position during his playing career, has advice for Patrick Mahomes: Sit out if you're feeling less than 100 percent.
"It kind of goes against everything I stood for when I played. But, you got to be smart. You've got to be smart," Favre told TMZ Sports.
Mahomes is in the NFL's concussion protocol after taking a hit to the head in Sunday's divisional-round win over the Cleveland Browns. Such a protocol did not exist until 2011, a year after Favre's retirement.
The Hall of Famer says he's far more cognizant of head injuries now than he ever was during his playing days.