The 19-year-old signed a contract with the Blues in December but, as part of the deal, he remained with Fluminense until the end of the season.
Moraes expects the Brazilian to link up with the Nerazzurri squad on their tour of the United States.
"We are truly only a step away from completing the deal," he told FCInterNews. "We are really only a few details away from the transfer.
"At this point, if all goes well, he should meet up with the team in the United States. We were told it was a straight loan and I think the teams are discussing those terms.
"Inter have already agreed terms with the player. There's no problem."
Wallace cost the Blues £4.7m.