From the scouting page;
Scouting Combine: Every player in the upcoming draft class will show up to be measured. You can send a scout to the combine to learn the ages and heights of all 48 players in the upcoming draft class.
Group Demonstration: In order to help get their names out there, all of the players your scout estimated to be 1-ball or 2-ball prospects have offered to arrange a demonstration of their skills. This option is equivalent to scouting each of these players once, though it will not provide any additional information for players you have already scouted.