Ancelotti, making his World Cup debut as a coach, says he is convinced he has a team capable of competing with the very best.
"It's a new experience, it''s a new responsibility to represent the country of football," the Italian said on Friday.
"We have a team that can compete with every team in the world, we're convinced of that. It''s a team with quality and experience, and with absolute confidence that it can compete with anyone," he added.
Brazil labored through their South American qualification campaign, losing six of 18 matches to finish fifth, which in previous years would have forced them into the play-offs.
Forwards Rodrygo and Estevao are out of the squad due to injury, while fading superstar Neymar will miss the opening game as he recovers from injury. Neymar has not played for his country since 2023.
That all puts pressure on Vinicius Junior, who scored 22 goals last season for Real Madrid and must provide the firepower if Brazil are to shine.
The Brazilians face a tough test against Morocco who stunned the football world four years ago when they became the first African side to reach the last four of a World Cup in Qatar.
They were awarded this year's Africa Cup of Nations title on home soil after a chaotic final, initially won 1-0 by Senegal after extra time.
Senegal were stripped of the victory after storming off the pitch in protest at a late penalty decision.
Coach Mohamed Ouahbi, who replaced Walid Regragui in March, said: "It's a match that will tell us where we stand, but I think we're in a good place to start this competition.
"Lots of people say it's not the Brazil of old, but it's still Brazil," he added.