Luiz Felipe Scolari's men go into the World Cup as favourites having defied the world and European champions with a 3-0 triumph last summer, despite la Roja having won the last three major competitions.
Spain could face Brazil in the second round if one team finishes top of their group and the other finishes second, but Fabregas does not fear a repeat occurrence of their shock defeat in South America.
"I believe [championship wins] are vital," the Barcelona midfielder said in a new self-interview to mark the launch of PUMA Tricks.
"In 2008, nobody believed in us and since then we've made a name for ourselves and we've become a competitive team that has won everything.
"We're not scared of Brazil. I think Brazil are a very strong team... and if we face them again it will be a completely new game."
Four years ago, a surprise opening loss in South Africa threatened to derail Spain's World Cup bid and Fabregas hopes that the squad will learn from their struggles in the last tournament.
"We lost in the last World Cup in the first game against Switzerland so it does bother me, it worries us, because we want to win," he added.
"That was a difficult time and I remember that we were all very nervous.
"Everyone thought it was the easiest game in the group. That was a lesson and we should remember it ahead of this World Cup too."
Fabregas is among a number of global superstars who will be sporting the new PUMA Tricks boots in Brazil this summer.
For more information on the PUMA Tricks boot and Nature of Believing, visit PUMA FC.