baseball player vs player

baseball player and player both are nouns.

Word	Noun	Adjective	Verb	Adverb
baseball player	Yes	No	No	No
player	Yes	No	No	No

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

Other hypernyms of baseball player include athlete, jock, participant.

baseball player (noun)	player (noun)
an athlete who plays baseball	a theatrical performer
	a person who participates in or is skilled at some game
	someone who plays a music as a profession
	a person who pursues a number of different social and sexual partners simultaneously
	someone who takes part in an activity