The captain underwent surgery earlier this month after picking up his left knee injury on international duty, with his recovery expected to last until mid-2024.
Despite losing the country's top scorer, Diniz is not expecting a new hero to emerge in a young team brimming with talent set to face Colombia on Thursday and world champions Argentina on Tuesday.
"Nobody has to worry about taking over Neymar's role. We have an extremely talented generation," the interim coach told reporters on Wednesday.
"Many can take on this role, but it's important that we don't put that weight on them. The players have to feel light and do their best. They'll naturally take centre stage."
Diniz said players such as Barcelona's Raphinha, Real Madrid's Rodrygo and Vinicius, or Arsenal's Gabriel Martinelli and Gabriel Jesus can shine in Neymar's absence.
The 39-year-old coach, recently crowned in the Copa Libertadores, also called up teenage prodigy Endrick to play for the five-time world champions for the first time.
"(Endrick) is here because of his merit and enormous future potential," Diniz said.
"We don't have to expect everything from a 17-year-old Endrick. I see huge potential. He could become one of those legendary players in Brazilian football, but time will tell," he said about the Palmeiras forward, who will join Real Madrid in July.
Brazil are third in the South American qualifying group, level on seven points with second-placed Uruguay and Venezuela in fourth, behind Argentina on 12 points after four games.
Colombia are fifth on six points.
