The centre-back made his first international appearance since signing for the Reds in the summer, as the South Americans faced Honduras at Miami's Hard Rock Stadium on Friday night.
Wearing the no.2 shirt at the heart of the defence, 'Licha' helped to keep a clean sheet as a 16th-minute opener by his namesake Lautaro Martinez and a double from iconic forward Lionel Messi secured a comprehensive 3-0 win.
Messi's penalty in first-half injury time and sumptuous chip in the 69th minute were his 87th and 88th goals for Argentina in 164 games. Meanwhile, United defender Martinez has eight caps to his name, having made his debut in a 3-1 defeat to Venezuela back in March 2019.