free agent vs worker

free agent and worker both are nouns.

Word	Noun	Adjective	Verb	Adverb
free agent	Yes	No	No	No
worker	Yes	No	No	No

As nouns, worker is a hypernym of free agent; that is, worker is a word with a broader meaning than free agent:

Other hypernyms of free agent include actor, doer.

free agent (noun)	worker (noun)
someone acting freely or even irresponsibly	sterile member of a colony of social insects that forages for food and cares for the larvae
(sports) a professional athlete who is free to sign a contract to play for any team	a person who works at a specific occupation
	a member of the working class (not necessarily employed)
	a person who acts and gets things done