Sources with direct knowledge tell TMZ ... the Colombian singer will not be participating in the halftime show with Usher and co. come Sunday, even though a lot of people assumed that might be since he showed up in the short film that Apple dropped Thursday.

As it turns out ... we're told Balvin is actually in Brazil right now and will be performing at Carnival on Super Bowl Sunday -- so he'll be far away from the action going down in Vegas.

Not only is he technically booked on the same night of the SB ... our sources say his focus right now is on his upcoming international tour -- "Que Bueno Volver a Verte" -- that kicks off in April in Germany. Plus, we're told he's in the middle of rehearsing for Coachella too.

Now, if you're wondering why JB was even featured in the Apple promo to begin with -- which also had Ludacris, Lil Jon and Taraji P. Henson in there -- we have an answer.

Our sources say the point of the promo was to highlight Usher's biggest collaborators over the years -- and Balvin is one of those lately ... they have their song 'Dientes' together.

In terms of who will actually come out for Usher's performance ... it's almost a given that Luda and Jon will join him at some point -- and we first reported ... Alicia Keys is for sure going to be onstage with Ursher.

Another person we know has been spoken to about potentially coming on as a special guest in none other than Justin Bieber -- but it's unclear if he'll actually perform or not for now.