Argentina began their World Cup campaign with a shock loss to Saudi Arabia but have since overcome adversity to come within a step of a long-awaited third world title.
"Since I started playing in this team, we are getting better and better. We are not the Copa America team. We are not the Finalissima team. We are one step ahead," Martinez told Argentine newspaper Clarin.
"We have to believe in great things. Believing it and working for it is something that identifies us a lot, with respect and ambition... We already have the talent.
"I dream of returning to Argentina and doing the Olympic lap with my team mates at the Obelisco."
Martinez said Argentina had suffered in the last-16 clash with Australia and the quarter-final against the Netherlands, after having both games under control.
"This time at halftime we talked and said to each other 'don't let the same thing happen to us'. We had to kill it off. And defensively we played very well. Up front we have four world-class monsters,"
Martinez has been key to Argentina's progress with match-winning saves against Australia and in the penalty shootout against the Dutch.
After another fine performance against Croatia, team captain Lionel Messi referred to Martinez as a beast.
"I love him (Messi). What he did in the Copa America was huge, but what he is doing in this World Cup is something I've never seen in my life," Martinez said.
Messi confirmed he will play his last World Cup match in Sunday's final where Argentina will face the winners of Wednesday's last-four clash between France and Morocco.
