The Paris Saint-Germain defender says he still has a chance to make Luiz Felipe Scolari's 23-man squad and will fight for his place in the Selecao.
The Brazil international has not represented the Selecao since 2009 but believes he could yet add to his 18 caps, won over a six-year period starting in 2003.
At 31 years old, the PSG stopper concedes it will be hard to force his way into Scolari's plans, but has not given up hope of playing at Brazil 2014 despite competiton from teammate Thiago Silva, Chelsea's David Luiz and Bayern Munich's Dante.
“It is very difficult to integrate into the Selecao because the competition is fierce on all lines,” Alex told PSG's official website. “Pundits are saying that three defenders are almost certain to participate in the World Cup, as coach Luiz Felipe Scolari seems to want four that means I still have a chance.
“If I continue performing well during the next four months, I can do it. In any case, I believe.”
Since joining PSG from Chelsea in 2011, Alex has become a key member of the Parc des Princes outfit – helping it to the Ligue 1 title last season.
On playing for Laurent Blanc's side, the former Blues center back was extremely complimentary with particular focus on the Parisians' ability to keep the ball in the opposition's half.
“The more you play in the opposing camp, the less danger for the defense," the defender said. “No matter which team we play against, we must have an aggressive temperament. Here, no defender has no problem with that.”