Yes, a player's scholarship can be rescinded anytime after the conclusion of the job change period. Simply go to 'Manage Roster' underneath the Coaching menu.
When you get to the manage roster screen, click on 'rescind scholarship' next to the player's name.
Important Note: Keep in mind that rescinding a scholarship of a player who you signed may make recruiting for your school more difficult in the future. Withdrawing scholarships impacts your coaches loyalty rating. This can be done sparingly with little to no negative impact.
If this is done too frequently it will hurt your coach's loyalty rating and because no kid will want to play at a program which isn't loyal to its players. Also, cutting a player could cause other players to leave as well.