Brazil striker Hulk limped out a training session on Sunday morning but said his injury was not serious and he expects to be fit for the World Cup Group A match against Mexico on Tuesday.
Hulk scored a goal in the practice game but limped off moments afterwards looking downcast.
"I felt a niggle and came off as a precaution," he told reporters shortly before the squad was due to fly 1,350 miles to the northern city of Fortaleza.
"I am good, I am happy and I hope to be 100 percent in two days for the next game. I hope it wasn't anything serious, I feel good.
"It's a normal pain," he added. "If I feel anything at all I come off to treat it."
Hulk had a similar issue ahead of the opening 3-1 win over Croatia last week but he played 68 minutes before being replaced by Bernard.
The burly striker, who is nicknamed after the comic book hero, has been a favourite of Luiz Felipe Scolari and is looking forward to playing in Fortaleza.
"I am from the northeast and my family is going to be there," he said. "It is a game that I don't want to miss. I want to play and I am going to be ready, God willing."
Mexico beat Cameroon 1-0 in their opening match