The 34-year-old, who has established himself as the hosts' undisputed number one in recent years, recently joined MLS side Toronto FC on loan following a lack of game-time with Queens Park Rangers.
His dearth of action called his starting spot into question, but Cesar says he is all set for his side's latest World Cup challenge.
"I have made it clear that I really primed myself for this World Cup regardless of the fact that some critics did not agree with my choice of going to play in a league that is in theory not strong," he's quoted as saying by Goal.com.
"I can look in the mirror and say I believe in myself. I made an important save against Mexico to help us get a draw and physically and mentally I am prepared."
Brazil need a point against Mexico to secure their spot in the last 16 of the tournament.