This is the 3734th most frequent Korean word.
선수들을
"Players" or "athletes" (plural, object form).
In this sentence, '선수들을' is used as the object of the verb '훈련시킵니다' (to train), referring to the people who are being trained, specifically the soccer players.
축구 코치들은 선수들을 열심히 훈련시킵니다.
Soccer coaches train the players diligently.
Here, '선수들을' functions as the object of '응원했습니다' (cheered for), indicating the group that receives the cheering, specifically the players.
관중들은 경기 후 선수들을 응원했습니다.
The spectators cheered for the players after the match.
In this instance, '선수들을' is again used as the object, specifically for '찾고 있습니다' (are looking for). It signifies the individuals being searched for by scouts, i.e., players.