The two-time World champions struggled to break down the tournament debutants for large spells of the encounter but took a 19th minute lead with Sergio Aguero's first goal at the FIFA World Cup.
However, it took Iceland just four minutes to find the equaliser at the Spartak Stadium, through Alfred Finnbogason.
"I get the feeling there's an anger at the heart of the team," he said, as quoted by BBC Football.
"It's a disgrace. Not having prepared for the match knowing that Iceland are all 1.90m tall," the 1986 World Cup winner told Venezuelan television.
Maradona stopped short on pinning the blamed on Lionel Messi, despite the captain missing a penalty in their Group D clash.
"I don't blame the players. I could blame the lack of work rate. But I can't blame the players, much less Messi, who gave it all he had," he said.
"I missed five penalties on the spin and I was still Diego Armando Maradona. I don't think that they dropped two points because Messi missed a penalty."