A tearful David Luiz was taken aback by the news Neymar would miss the rest of the World Cup and pledged to win the trophy for the injured attacker.
The hosts and favourites disposed of Colombia 2-1 in an enthralling quarter-final in Fortaleza on Friday, thanks to a bundled Thiago Silva effort and Luiz's exquisite long-range free-kick.
A mouthwatering semi-final clash with Germany now awaits, although they approach that match without star man Neymar.
The 22-year-old, so key to the Selecao, left the field on a stretcher in the closing stages after taking a knee in the back from Juan Zuniga.
News quickly emerged that Neymar had sustained a fractured vertebra and would miss the rest of the tournament - information that had not reached man-of-the-match Luiz when he came through the post-match mixed zone.
"We have made a pact to support him, to be by his side and also to show the strength of the team," he said. "We are very worried. We are going to pray for him because Neymar should be on the pitch."
However, a reporter informed him that Brazil's doctor, Rodrigo Lasmar, had confirmed the severity of the injury - news that hit Luiz hard as his eyes welled with tears.
"I am speechless," he said. "Neymar is a boy that fights a lot and dreamed about playing in a World Cup.
"He is a boy that only invests in the good things for football: happiness and magic. And now, he will be out of the final because of a foul the defender probably should have avoided.
"Brazil will suffer a lot because of this loss but Neymar will keep helping us with happiness. He is a boy. He will surely grow because of this moment."
He added: "We will try to win the competition for our people, for Brazil. Of course now he is out of the games and everyone is sad and it would be great if we could win it now and celebrate with him."
Brazil will also be without captain Silva for the semi-final through suspension, but it is the injury to Neymar that has dominated the headlines here.
It has inevitably led to focus falling on the perpetrator and, while the Zuniga insists it was not intentional, FIFA's disciplinary committee is studying the challenge, which went unpunished by the officials.
Neymar's team-mates have rallied around him but the overriding emotion is more of sympathy for the attacker than anger with the challenge.
"Angry? No, I didn't see the challenge and after the game I haven't seen the video of it," Luiz said. "But I never crucify players because in a person's life you do things and you are emotional at the time and don't think.
"So I just say if he did it with bad intentions because he wanted to injure him, then I think now he will feel sad, but if he just tried to stop the game that is natural. That's football."
Legendary former Brazil striker Pele does not believe the injury to Neymar will end their chances of glory, pointing to his own experience in 1962.
"@neymarjr was raised in my @santosfc and it hurts our hearts to know that he can no longer defend Brazil in the World Cup," he said.
"I was also injured during the 1962 World Cup in Chile, and I was out for the rest of the tournament, but God helped Brazil continue on to win the championship.
"I hope the same will happen with our Selecao in this World Cup."
Neymar's international team-mates also took to social media, with Brazil and Chelsea midfielder Willian tweeting: "Have strength brother. @neymarjr we are together with you, we love you."
Striker Fred's lengthy Facebook post included a drawing of Neymar being surrounded by fans.
"We have one more reason to play with heart in this cup," Fred said.
"Neymar, rest assured that our group loves you and give life to win this title for you. You were and continue to be the ace and the soul of our team.
"The whole of Brazil is praying for you!"
Barcelona team-mate Lionel Messi, also a semi-finalist with Argentina, added: "Neymar, I hope you recover very soon friend!"
The fallout to Neymar's injury took the shine off Brazil's progression and diverted attention away from Luiz's goal-of-the-tournament contender.
From 35 yards out, the defender hit an incredible right-footed free-kick which dipped just under the crossbar and out of the reach of David Ospina to double Brazil's lead in style.
"I train a lot to do things like that," Luiz said of the goal. "Everyday I train a lot and practice a lot.
"I had the ball at just the right spot and when I saw it moving in the air so much I knew it would be difficult for the goalkeeper. I was so happy."