Christian McCaffrey's Halloween TikTok With Olivia Culpo Upsets Fantasy Owners

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!!

CMC -- who has yet to play this season due to bilateral Achilles tendonitis -- hilariously acted awkward and stiff throughout the skits ... but he clearly wasn't being held against his will, as he smiled and kissed the Mrs. at one point.

But some folks who drafted him this year aired their grievances about their beloved fantasy teams ... hitting the comments to remind the All-Pro running back about their woes with him sidelined.

As one user put it -- "I'm 2-6 in fantasy bc my first overall pick is hurt and dressed like the tin man😔"

"That was my first pick in fantasy, safe to say I’ve been depressed for 8 weeks of fantasy game play," another said.

The grade-A haters will eventually get their way ... as 28-year-old CMC is slated to make his return as early as Week 10.