学习了,wiki有相关资料可学习:http://en.wikipedia.org/wiki/Redshirt_(college_sports)
Athletes may be asked to redshirt if they would have little or no opportunity to play as an academic freshman
One reason is that the athlete may not be ready to balance the demands of academic requirements with athletic requirements
In college football, a student athlete may redshirt to increase size and strength toward the completion of overall physical maturity, desirable assets for many positions