"Brazil aren't as dependent on Neymar as they were in 2014," said Manchester City winger Sane.
"They are better positioned and have a few new stars, but it still makes a big difference whether Neymar plays or not."
Germany host Brazil in a mouth-watering friendly at Berlin's Olympic Stadium on Tuesday as part of both teams' build-up to June's World Cup in Russia.
It will be their first meeting since the Germans stunned Brazil with five goals inside half an hour in a 7-1 romp in the semi-finals of the 2014 World Cup.
Just as back then, Brazil forward Neymar is sidelined by injury. This time the world's most expensive player is recovering from foot surgery.
He is expected to be fit in time for the World Cup, which kicks off on June 14.
Brazil beat Russia 3-0 on Friday with three goals in 13 minutes by Miranda, Paulinho and a Philippe Countinho penalty at Moscow's Luzhniki stadium, which hosts the World Cup final on July 15.
Germany warmed up with a 1-1 draw with Spain in Duesseldorf as Rodrigo Moreno's early goal for the visitors was cancelled out by Thomas Mueller's first-half strike.
Germany head coach Joachim Loew has said the 7-1 rout will remain a subject "for the next 10, 20 or 30 years" whenever the teams meet.
"Football is almost something spiritual for Brazilians, so I can understand that the 7-1 still has an effect," said Sane.
"They live for football, but they will live their 'joie de vivre' again at the 2018 World Cup.
"They are a great team with a good mix of old and young players, they are technically strong, but they also have tough players in defence.
"They can't be underestimated, because they are clearly among the World Cup favorites."
Sane is expected to take Julian Draxler's place on the wing against Brazil while his Man City team-mate Ilkay Gundogan could replace Sami Khedira in the defensive midfield.
Loew has said he expects to make up to five changes from the team which drew with Spain.
Mueller and Mesut Ozil have been released by Loew to rest, while Liverpool midfielder Emre Can has dropped out with a back injury.