Chile coach Ricardo Gareca says Sheffield United striker Ben Brereton Diaz must learn Spanish.
On-loan from Villarreal, Brereton Diaz has been left out of Gareca's first Chile squad.
"I would like him to learn Spanish, I think it is important," Gareca said.
"He was called up for the Copa America two years ago, he has had enough time to [learn how to] speak Spanish," said Gareca.
"It is something that I personally told him, that I would like him to speak Spanish. I consider it essential for communication.
"Communication with his team-mates, with me, with the coaching staff, with the people [and] with the press."