Maradona left the two Inter stars out of his preliminary list for the trip to South Africa.
"I was really quite upset when I heard about it, knowing how much these two players care about representing their country," said the Nerazzurri President.
"Of course they deserved to be in the squad. It was truly a strange decision considering the incredible season that both of them are having.
"I am pleased for Diego Milito and Walter Samuel, but the great disappointment of seeing the other two left at home remains."