Messi is preparing for an emotional farewell in front of his home supporters as Argentina take on Benin at the Estadio Monumental, with kick-off scheduled for 8pm local time, which is 1am BST
The former Barcelona and Paris Saint-Germain star leaves Argentina with 125 goals in 207 caps, two Copa Americas, one World Cup and one Finalissima as he leaves behind a legacy that won't be forgotten.
Messi announced his decision to retire after the 2026 World Cup, in which he led his side to the final, only to be beaten by Spain by a single goal in what was a heartbreaking game.
Ahead of his final clash with Benin, Scaloni has spoken on Messi, who he admits will be sorely missed as Argentina seek a replacement before the next major tournament.
"Messi leaves behind something unequalled," Scaloni stated, as quoted by ESPN. "We have to keep playing, but the feeling of having him on the pitch is unique. I've never seen anyone else convey what he does on a football field, and that is what we're going to miss.
"Only nostalgia remains now that he won't be there. He is an incredible example. The first to arrive, the last to leave, how he takes care of himself, how he faces each game.
"You can see he is a phenomenon just by how he plays, but he has things behind him that his teammates see, and he is the best example there can be. He has left - or is leaving, because he has one more game - something incomparable."
Nicolas Otamendi, who also announced his international retirement after the World Cup, has been included in the squad for Tuesday's fixture. He will start his final international appearance, likely alongside Cristian Romero in central defence as Argentina seek a win in what is a historic game.