Chelsea won't welcome new signing Wallace until next season.
TMW says a fee between Chelsea and Fluminense was struck last week, which includes Wallace remaining on-loan when the deal goes through in January.
Flu want to keep the fullback for their Copa Libertadores campaign and Chelsea have agreed to loan back the youngster for the second-half of the season.
In July, he will take part in the U20 World Cup with Brazil before joining Chelsea for preseason after the tournament.