The Zenit forward played 68 minutes of the opening-day Group A win over Croatia before being replaced by Bernard.
However, Hulk was not able to complete Brazil's latest training session after picking up a thigh problem.
Speaking at a press conference later on Sunday, Hulk looked to play down concerns over his fitness ahead of Tuesday's meeting with Mexico in Fortaleza.
"Today during training I scored two goals and I was feeling a little bit of discomfort," he said. "So I went out as a precaution.
"I felt it on my back left thigh, I felt a bit of discomfort for a few days, but I wasn't going to miss the first game.
"And if God wills it, I don't miss the next game. I'm going to work on this. I'm going to travel with a focused mindset for this game against Mexico, and if God wills it, I'll be able to go onto the pitch and help the Brazil squad.
"The person who is going to decide is Luiz Felipe Scolari. It's up to him to decide and see how everything is going. If I go on the pitch, of course I'm going to give it my all, I'm not going to be in pain, and I'm going to go after every ball.
"I want to play in every game. Of course, I can't put the whole squad in jeopardy. I felt discomfort, so I need to give myself time to be good for the game.
"I am going to take these two days to play in the game and help the Brazil squad."
