Christian McCaffrey apparently can't have a little Halloween spirit while he nurses his injury ... 'cause the 49ers superstar adorably showed off his couples costume with his wife, Olivia Culpo -- and fantasy football owners ain't having it.
CMC and OC chose to be the Tin Man and Dorothy from "The Wizard of Oz" this year ... even getting in character for a few TikToks to really bring it home.
In fact, they got their adorable pup, Oliver Sprinkles, to be Toto!