The 17-year-old joins the Reds having been part of the Brazil squad that won the FIFA U17 World Cup on home soil last November.
He was then named on the bench for two Fluminense fixtures in Serie A last season and he worked with Alisson Becker’s brother, Muriel, at the Brazilian side.
Pitaluga has now started training at Melwood, where he will be based with the first-team group, alongside playing for the club’s Academy teams.
“I saw him for the first time in the World Cup squad. You’re checking all the goalies and looking at the ages,” head of goalkeeping John Achterberg told Liverpoolfc.com.
“You see that he was in the World Cup squad one year younger than the rest of the squad, then you think that’s worth a look because normally you have two goalkeepers of the same age, but if you have someone who is a year younger you think he may have some good attributes.
“He was at Fluminense; we got some games to look at, all the other goalie coaches also look at it – Jack [Robinson] and the Academy coaches Mark [Morris] and Taff [Neil Edwards]. And, of course, I speak to the gaffer and the rest of the coaching department here.
“In Fluminense we had Allan [on loan], so I spoke to Julian [Ward, loan pathways and football partnerships manager] if he saw a little bit of him in training there. He saw him too and was also positive.
“I asked Ali to speak to his brother to see how it goes and how he is doing. Ali spoke to his brother and Ali went training there. We saw a little bit from the training and the games he was playing for the reserves in Brazil.
“He was already 16 playing in the reserve team there so you also think, they trust him to play already in the reserves at 16.”
Achterberg added: “Now he is here, we have to improve [him]. He is still young, there is no pressure because there is still a long road and we don’t want to create any pressure for him because there is still work to do.
“First of all, you need to let him settle down, find his way. He needs to learn the speed, the kind of game in England is different than in Brazil, it’s a lot faster and there’s more aggression in it. All that stuff you have to calculate as well to work on a little bit.”