MVP vs most valuable player

MVP and most valuable player both are nouns.

Word	Noun	Adjective	Verb	Adverb
MVP	Yes	No	No	No
most valuable player	Yes	No	No	No

As nouns, MVP and most valuable player are synonyms defined as:

MVP and most valuable player: the player judged to be the most important to the sport

MVP (noun)	most valuable player (noun)
the player judged to be the most important to the sport	the player judged to be the most important to the sport