While the U.S. are tracking the midfielder, who has been one of the top performers in Liga MX this season, they have not been in direct contact with him, sources added to ESPN Mexico.
Zendejas, born in Mexico but raised in El Paso, Texas, previously played for the U.S. at the youth national team level, including at the 2015 Under-17 World Cup. Since then, he's featured for Mexico in two senior international friendlies in late 2021 and early 2022, although recent questions have been raised regarding his eligibility.
A representative for U.S. Soccer confirmed to ESPN that they're following the player, but noted that the development isn't new due to Zendejas' previous involvement in the U.S. national team structure, which they said means he remains part of their player pool.
Without a one-time switch recognized by FIFA, the 24-year-old would be ineligible to play for Mexico, including in the two friendlies he appeared in.
FIFA told ESPN last month that they were investigating the matter.
After the in-form Zendejas' surprising absence from Mexico's latest roster for a friendly against Paraguay in August, ESPN Mexico reported that Zendejas had yet to file the one-time switch that would commit him to El Tri going forward.
Following a 1-0 loss in the friendly, Mexico manager Gerardo "Tata" Martino claimed that "it's almost an extortion" for Zendejas to delay officially switching to Mexico, suggesting that him doing so was tied to whether he would be selected for this year's World Cup.
Those comments led to criticism from Zendejas' Club America manager Fernando Ortiz, who cautioned Martino to "watch what you're saying."
TUDN reported earlier this month that the Mexican Football Federation (FMF) wanted Zendejas to sign the one-time switch right before he was about to board a team bus with Club America. Zendejas, however, asked for more time to read the full document.