Milito, one of six strikers in Maradona's 23-man squad, reached the heights of European football by scoring both goals in Inter Milan's 2-0 win over Bayern Munich in Saturday's Champions League final in Madrid.
"I'm not surprised by Milito. He's had a spectacular season, but then so have the others, Lio (Messi), (Carlos) Tevez, 'Kun' (Sergio Aguero)," Maradona told a news conference.
"Milito has proved me right for picking him. Whoever is in the best form will play," said Maradona, whose first-choice pair appear to be Messi and Gonzalo Higuain.
"There are no first-team players and no reserves (in the squad)," added Maradona, who wiped his face with a towel after his players practised in a downpour at their training base.
Maradona, whose team face Canada in a farewell match at River Plate's Monumental stadium on Monday, said the players were all in great spirits and anxious to work towards the South Africa finals starting on June 11.
"In 1986 we had a build up of 70 days, today we are barely 20 days away and I still don't have my full 23," said Maradona. Milito, Inter team mate Walter Samuel and Bayern's Martin Demichelis had not yet joined up with the squad.
"But the players have understood that you experience the World Cup the way we are living it," said Argentina's 1986 World Cup-winning captain, who has often stated that he knows what it takes to win the trophy.
"I want to have them all sharp... We can give anyone a good fight, a footballing fight, because we have a good game and good players. This squad are similar to that of '86 because they have hunger for glory."
Argentina face Nigeria, South Korea and Greece in Group B at the finals in South Africa.
Maradona, who had criticised Inter coach Jose Mourinho for his side's ultra-defensive performance in the second leg of their Champions League semi-final away to Barcelona, said he would not give up on attack come what may.
"Not at any price. If I renounced attack it would be a sin with the players I have," he said. "I think that if we play the way we should we'll do well."
