If there is no Profile Publish Access set for coaches to see students information, then they will not see the list displayed in the Roster Tab. 

To fix this, navigate to:
  1. From the menu in the top left select Core
  2. Navigate to Security > Profile Access > Profile Publish Access
  3. In the choose the roles for which drop-down select Student
  4. Click Edit
  5. Mark the check box for Student to Coach
  6. Click Save
  7. Click on Student to Coach
  8. Click Edit
  9. Select the fields you would like coaches to see
  10. Click Save & Confirm