The 28-year-old received a call-up from Brazil head coach Luis Felipe Scolari earlier this week for their international friendly against South Africa in March.
Fernandinho, who joined City from Shakhtar Donetsk last summer, has played a central role for Manuel Pellegrini's side this term, scoring three goals in 20 Premier League games so far.
As a result, Fernandinho has been recalled to the Brazil setup and admits playing in this year's World Cup would be a dream come true.
"It is a dream for me to play in the World Cup in my country; it is maybe the most important thing in my career," he said.
"The next one in Brazil might be in a hundred years. It's the only opportunity. I put it in my head that if I played well for Manchester City, then I had a chance to get myself back in the national team.
"After a few months with good performances by myself and by my team-mates, it shows they have paid attention in Brazil."
City playmaker Fernandinho also revealed his compatriots at Stamford Bridge were quick to commend his return to the national side.
"The Brazilian players at Chelsea sent me messages and congratulated me," he added.
"They said I deserved this call-up by the national team. And we are friends, so they say I deserved it and I thanked them."