The Selecao registered wins against Croatia and Cameroon and a goalless draw against Mexico to reach the knockout stages, but the five-time World Cup winners came under scrutiny after failing to beat the Central American nation.
Scolari told reporters: "We can improve a bit more and we will have to do so if we want to overcome Chile, who are good. They have malice, they are organised and have a lot of quality.
"I liked the way my team played. The fact is that we have improved in our passing and our marking. We still need to put more pressure on midfield."
Brazil take on Chile this Saturday in Belo Horizonte.