Argentina beat Ecuador 1-0 thanks to a free-kick from Lionel Messi, who was replaced by Exequiel Palacios with 3 minutes left in the match.
"In the end I was a little tired. It happened like that. It probably won't be the last time I start going out during games, but I felt very good. It was a difficult game to play, very physical, very hard, but I felt very good," he said.
Lionel Messi had not come out of substitution in an official competition with the Argentine National Team since June 2014, when he was replaced by Ricky Alvarez against Nigeria in the World Cup in Brazil.