What happened: The 39-year-old announced his international retirement on Aug. 31, so his trip does not reopen the door to a national-team appearance. Any role around the match would be off the field rather than in the lineup against The Stallions.

Why it matters: That matters because any Messi appearance with Argentina now carries retirement-level attention, even in a friendly. It also keeps the focus on his exit from international soccer rather than a one-night return.

What to watch: Watch for any pregame or postgame appearance in Buenos Aires and for whether Messi addresses the crowd. After the international window, attention shifts back to his MLS stretch drive.