From FAQ:
Q: How does 'redshirting' a player work?
A: The term "redshirt" is used to describe a student-athlete who does not participate in competition in a sport for an entire academic year and thereby does not use one of his 4 years of athletic eligibility. Here are the rules for redshirting:
- Any given player can only be "redshirted" once in his career (and possibly another medical hardship year to be added in a later release)
- A player can have a redshirt year any of his four years
- A player can be tagged as a redshirt if:
- the coach has seasons remaining on his account
- the player has not yet played a single minute that season
- he has not already been redshirted at some point in his career
- no one else is currently being redshirted - Any player who has been tagged as a redshirt can be untagged at anytime during the season
- Teams can redshirt a max. of 1 player per season
- Redshirted players will still practice with the team
- Redshirted players will NOT dress for the game, meaning no matter the situation, they will not be used in a game.
- Exhibition games do NOT count when determining redshirt eligibility.
Emphasis added.