It has always been my understanding that if you play one play in one game blows your redshirt, unless there are medical reasons of course...
Redshirt Rules Question- Freshman Playing Time
"Players, especially in football, may redshirt to learn the team's play book since college teams run more complex and more plays generally than most high school teams. In other cases, a player may be granted a redshirt if he or she has participated in less than 10% of the season taking place in an academic year."
I'm actually digging around the NCAA website looking for confirmation about that, too. I've seen it used in other sports before, but I can't remember seeing it in football - probably because if someone participates that little, I wouldn't notice it anyway.
In Division I, a student-athlete can apply for a hardship waiver if a season-ending injury or illness occurs in the first half of the season. The student-athlete, however, must not have participated in more than two contests or dates of competition or 20 percent (whichever is greater) of the institution's scheduled contests.
It would later say the hardship waiver is often confused with the general redshirt in which a players DOES NOT compete. So I assume this 10% is supposed to be 20% or 2 games (which ever greater) for a medical purpose only.
I think this is correct. I vaguely recall that we had a few players who did this. Like they played one series on special teams during the year, but still managed to get a redshirt.
Technically, they burned their redshirt when they played in that series, however, they can apply to be granted a redshirt by the NCAA by citing the fact that they only played for so little. I believe the application process is a lot like the medical redshirt one. Sometimes it is granted, other times it isn't.
when i was in college ('99-'01)in the MAC the redshirt rule was you can play in non-conference games, but a play in a conference game and you lose your "redshirt" dunno about the medical redshirt, and i know the NCAA has occasionally granted a sixth year of eligebility either due to injuries or multiple transfers
The way it worked for me in 2003 was this. i played in less than 20 percent of our games, but i competed in the second half of the season, so a medical redshirt was thrown out. A regular redshirt is voided when you step on the field.