Di Maria appeared a certainty to miss Sunday's clash due to an adductor injury, which he suffered against Panama in the group stage.
However, Martino confirmed he was only without Augusto Fernandez and Ezequiel Lavezzi for the decider at MetLife Stadium.
"Except Augusto and Lavezzi, the rest of the players are available," he told a news conference.
For the second time in as many years, Martino's side take on Chile in a bid to be crowned champions of South America.
The former Barcelona coach wants a different result this time, having been beaten on penalties in Santiago last year.
"With respect to last year, I would like to change the result," Martino said.
He added: "The two teams arrive well and it's not worth making the comparison with last year."
Martino has an in-form Messi at his disposal, with the Barcelona star having scored five goals at the tournament so far.
"Messi is the captain of the team and represents what we all want – to win the final," he said.