baseball manager vs handler

baseball manager and handler both are nouns.

Word	Noun	Adjective	Verb	Adverb
baseball manager	Yes	No	No	No
handler	Yes	No	No	No

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

Other hypernyms of baseball manager include coach, manager.

baseball manager (noun)	handler (noun)
a coach of baseball players	(sports) someone in charge of training an athlete or a team
	one who trains or exhibits animals
	an agent who handles something or someone