Mark Zeigler of the San Diego Union-Tribune had a story on the possibility of Mexico-Argentina in San Diego on June 4. The story probably went to print before the Argentine FA posted the news late last night that it had indeed accepted the mini-tour of North America in June, which includes Mexico-Argentina on June 4.
It's a Wednesday night and, as Zeigler points out, the match would be Mexico's 17th game in San Diego. But often the opponents have left something to be desired. Mexico has played Venezuela, Sweden, Albania and Paraguay there in recent years - two decent (though undermanned) sides and two walkovers.
If Mexico drew a record 63,328 to San Diego for the Venezuela game last year, I can't imagine Argentina not breaking that in June.