A few days later, at the news conference where he made his move to the United States official, Hernández was less humbled. He did not play down his European successes, which are many. He started his career abroad with Manchester United, winning two Premier League titles with the club, and then had a brief stint with Real Madrid, distinguishing himself as a reliable substitute. He went on to join Bayer Leverkusen in Germany, then returned to the Premier League with West Ham, before finally landing in Seville.

“Imagine coming back as a Mexican soccer legend,” he said of his return to North America.

The boast struck a nerve in Mexico.

The country has long had a complicated history with its sports stars, and especially with the members of its national soccer team. Players like Hernández and others are revered for their successes, but vilified for even the tiniest weakness. The attitude plays itself out in reactions from the stands, and in often-confrontational coverage in the Mexican news media. At times, the pressure has grown so intense that Mexico coaches have hired mental coaches to help their players navigate it.

In that context, then, it was not surprising that some viewed Hernández’s comments before and after his arrival in Los Angeles — and even his decision to join M.L.S., which many of his compatriots deride as a step down from the challenges players face in Mexico’s top league, Liga MX — as an unforgivable slight.