Lionel Scaloni admits it was difficult to leave players out of Argentina's 2019 Copa America squad but is confident he has chosen the country's 23 best players after snubbing Mauro Icardi.
Aguero has enjoyed another strong season at club level and will be confident of transferring that form to the Copa, where he will be joined by City team-mate Nicolas Otamendi.
Lionel Messi is expected to captain the team as one of the senior stars, while Matias Suarez – also 31 years of age – is a surprise inclusion among the strikers, with the River Plate man having won his only two senior caps this year.
There is also a shock in defence, with Milton Casco chosen ahead of Gabriel Mercado, a mainstay over the past few years. Manchester United pair Sergio Romero and Marcos Rojo also miss out.
While conceding he had doubts during the selection process, Scaloni is now content he has a squad capable of winning the tournament for the first time since 1993.
"We believe that these are the best players we have at this moment," he told a media conference. "Some were left out due to injury, but they were always in consideration.
"When you have so many players of a good level to choose from, there are always doubts. It is difficult to explain everything, but the final decision is always about what is best for the team.
"We suffer when we have to leave a player out. It's our job, but it's not easy for us.
"We want people to identify with all these guys. We are convinced that they are the best for the moment. We are clear about what we want and we know what our idea is."
"Colombia is one of the most powerful teams in South America; they have great players," he added.
Argentina Squad In Full
Goalkeepers: Franco Armani (River Plate), Agustin Marchesin (Club America), Esteban Andrada (Boca Juniors)
Defenders: Juan Foyth (Tottenham), Nicolas Tagliafico (Ajax), Renzo Saravia (Racing Club), German Pezzella (Fiorentina), Ramiro Funes Mori (Villarreal), Milton Casco (River Plate), Nicolas Otamendi (Manchester City)
Midfielders: Roberto Pereyra (Watford), Leandro Paredes (Paris Saint-Germain), Marcos Acuna (Sporting CP), Angel Di Maria (Paris Saint-Germain), Guido Rodriguez (Club America), Rodrigo De Paul (Udinese), Exequiel Palacio (River Plate), Giovani Lo Celso (Real Betis)
Forwards: Sergio Aguero (Manchester City), Lionel Messi (Barcelona), Matias Suarez (River Plate), Paulo Dybala (Juventus), Lautaro Martinez (Inter).