The 23-year-old Brazil international has been subjected to racial abuse on several occasions in Spain
Messi saw his spot kick saved by goalkeeper Hannes Por Halldorsson after Alfred Finnbogason had cancelled out Sergio Aguero's 19th minute opener.
"I don't blame the players," Maradona told Venezuelan television channel Telesur.
"I could blame the lack of work rate. But I can't blame the players, much less Messi, who gave it all he had.
"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."
Argentina take on Croatia on Thursday before their final group game against Nigeria next week.