Moura was called up by Scolari for a recent international friendly double-header against South Korea and Zambia, but played just 45 minutes across the two games.
Juninho believes that Scolari has doubts about Moura and is affecting his confidence with a reduced role for Brazil, insisting that the Paris Saint-Germain man is an excellent player who deserves better.
He told RMC: "He's just arrived in France, and still hasn't had a full season. He needs time. In nine internationals, he's started once and was taken off.
"The truth is that Scolari doesn't want Lucas, but he can't accept that. Little by little, he is making the player lose confidence.
"That often happens in Brazil. It's really a shame. Scolari doesn't really want Lucas. Little by little, he is forcing him out of the squad. I don't think he's over-rated. He's an excellent player."
The 21-year-old joined PSG in January, scoring twice in 20 appearances for the Ligue 1 champions.