Neymar scored four goals in three games in Group A as host nation Brazil sealed their passage into the round of 16, with Mexico joining them in the knockout phase.
The Barcelona forward bagged a brace against Cameroon on Monday to secure top spot and set up a do-or-die fixture with South American rivals Chile in Belo Horizonte on Saturday.
And while Willian believes the 22-year old is only going to get better as the tournament goes on, he insists the mercurial forward will not be carrying the burden alone.
"I don't think he's even gotten started yet," the Chelsea player told reporters.
"I think that the potential that Neymar has means he can do much more for the team. Everyone knows the quality that he has. But it should be made clear that he doesn't play alone.
"It will also depend on us to play well and help him. We're always here to help him. He brings us just as much joy to play together."
Willian also urged the public to forget about the past – in reference to Brazil's defeat to Uruguay in the 1950 World Cup final – the last time Brazil hosted the showpiece event.
Brazil eased into the decider only to be beaten 2-1 in front of over 170,000 spectators at the iconic Maracana and Willian said the team are determined to make their fans happy.
"We have to forget about the past and think only about the present," he said.
"Thinking about today, a lot of people have this memory when Brazil lost at home (to Uruguay in the final of the 1950 World Cup).
"There is always going to be a lot of pressure on Brazil to win. But us players are looking to be calm and relaxed and to take this pressure and look at the positive side.
"To bring it to a place where we can use it on the pitch to make us better, playing with happiness and relaxation, giving happiness to the Brazilian fans. This is what we are looking to do until the end of the World Cup."
