Grouping Basketball Athletes

Imagine being hired by a basketball team, such as the LA Lakers, as a data scientist tasked with scouting potential players. Your responsibility involves identifying basketball athletes with similar attributes, clustering them into smaller groups, and facilitating practice sessions that emphasize their strengths and address their weaknesses. You will develop a clustering model to categorize similarly scouted players together. How would you evaluate whether your algorithm successfully grouped similar players without having pre-labeled data available?