Sports scholarships are given on a yearly basis. Many athletes and their families make the mistake of believing that athletic scholarships last all four years of college, but that's not true.
It means that they award you financial aid one year at a time.
At the end of each year, scholarships are renewed by the coach and athletic department, provided that you remain eligible throughout the year.
You are allowed to be on athletic scholarships for up to five years in your college career. Coaches are able to adjust the amount of the scholarship at the end of each year when it expires. That means they can increase, decrease, or get canceled altogether.
In order to make sure that you maintain your good status and keep your scholarship, you need to make sure you do what is expected of you. As a student-athlete, that means keeping up in your classes, getting good grades, training and contributing to your team.
If for some reason you become ineligible in any way, the coach has full right to give your scholarship away to someone else.