Brazuca is a slur used to describe Brazilians in a derogatory way. Does not necessarily bear a negative connotation. It is used by Brazilians most often when depicting Brazilian athletes playing abroad.
The word Brazuca is a racial slur that has been used historically to degrade and dehumanize brazilians. The word is still used by some people for this purpose, and it is seen as offensive and hurtful to brazilians. If you are unsure about whether or not it is appropriate to use the word Brazuca, it is best to err on the side of caution and avoid using it in any situation.