Those Englishmen who sneered at Spain's Primera Liga as "Scotland in the sun" and claimed that there was no life below Spain's big two were suddenly muted.
Marcelo Bielsa's club were the best European side to come to Manchester for a while, as impressive as AC Milan in 2005 and 2007, or Real Madrid in 2003, and there was more than a hint of English arrogance in the days that followed.
Pundits blind to the merits of leagues outside England's self-satisfied, self-reverential top flight focused on United's perceived weaknesses rather than the brilliant Basques.
One former United player inquired over the likely price of the best Athletic talents such as Fernando Llorente, Iker Munian and Javi Martinez as if they were all desperate to be cherry picked.
When it was explained that Llorente turned down a £30 million (Dh172.5m) move to Liverpool, who then bought Andy Carroll, there was surprise.
Not every player wants to play in England and the Athletic players identify more with their club than any other. They are well paid by a big club where they are loved, they play glorious football and they are in the Spanish Cup final and the Europa League last 16.
Their best performers are playing for the European and world champions Spain. They are flattered by the attention, but this Basque triumvirate are happy where they are.