The Argentina boss announced an initial 29-man squad for the two warm-up matches against Ecuador and Guatemala, giving him time to assess his options ahead of this summer's Copa America in the USA.
Scaloni had already confirmed that Manchester United winger Alejandro Garnacho would be included when he named his final selection.
Speaking after Friday's 4-1 win over Guatemala, Scaloni told reporters: "Garnacho will be there [at the Copa America]."
Barco among Argentina omissions
While Garnacho will be present at the tournament, Scaloni has now confirmed which three players have failed to make the final cut.
The World Cup-winning manager has decided to leave out Brighton's Barco, Marseille's Leonardo Balerdi and Atletico Madrid's Angel Correa.
Barco was included in the provisional squad despite making just six Premier League appearances since joining Brighton from Boca Juniors in January.
The highly-rated defender was hoping to appear at his first major tournament after making his international debut in March.
However, Scaloni has opted to take Sevilla's Marcos Acuna and Lyon's Nicolas Tagliafico as his main left-back options.
Although he will be disappointed to miss out on selection, Barcoa is expected to represent his country at the Paris Olympics this summer.
Balerdi, Correa fail to make cut
Meanwhile, Balerdi was unable to convince Scaloni to select him over Lisandro Martinez, German Pezzella, Cristian Romero, Nicolas Otamendi and Lucas Martinez Quarta.
Correa was in the squad at the 2021 Copa America and the 2022 World Cup, but the Atletico Madrid attacker has failed to make the cut for this summer's tournament.
The 29-year-old has been on the periphery of the squad for some time, having failed to start any of his last 10 international appearances.
Argentina will begin the defence of the Copa America in Thursday's clash with Canada at Mercedes-Benz Stadium in Atlanta.
Argentina's Copa America squad
Goalkeepers: Emiliano Martinez (Aston Villa), Franco Armani (River Plate), Geronimo Rulli (Ajax)
Defenders: Gonzalo Montiel (Nottingham Forest), Nahuel Molina (Atletico Madrid), Cristian Romero (Tottenham Hotspur), Nicolas Otamendi (Benfica), German Pezzella (Real Betis), Lucas Martinez Quarta (Fiorentina), Lisandro Martinez (Manchester United), Marcos Acuna (Sevilla), Nicolas Tagliafico (Lyon)
Midfielders: Rodrigo De Paul (Atletico Madrid), Alexis Mac Allister (Liverpool), Enzo Fernandez (Chelsea), Leandro Paredes (Roma), Guido Rodriguez (Real Betis), Exequiel Palacios (Bayer Leverkusen), Giovani Lo Celso (Tottenham Hotspur), Valentin Carboni (Monza)
Attackers: Lionel Messi (Inter Miami), Angel Di Maria (Benfica) Lautaro Martinez (Inter Milan), Julian Alvarez (Manchester City), Nicolas Gonzalez (Fiorentina), Alejandro Garnacho (Manchester United)