soccer player vs participant

soccer player and participant both are nouns.

Word	Noun	Adjective	Verb	Adverb
soccer player	Yes	No	No	No
participant	Yes	No	No	No

As nouns, participant is a hypernym of soccer player; that is, participant is a word with a broader meaning than soccer player:

Other hypernyms of soccer player include athlete, jock, player.

soccer player (noun)	participant (noun)
an athlete who plays soccer	someone who takes part in an activity
	a person who participates in or is skilled at some game