Mexico's problems are mounting ahead of the World Cup, with Hector Herrera missing training in Copenhagen on Wednesday and Diego Reyes still a major injury doubt.
The Mexican federation released a statement Wednesday to announce that Reyes, a Porto midfielder, had been given time off until Thursday, with ESPN's John Sutcliffe indicating that the motive for Herrera's leave was family issues caused by an alleged party following Saturday's 1-0 victory over Scotland in Mexico City.
Reyes is still recovering from a hamstring injury and is yet to train fully with his teammates, putting his World Cup in doubt. He hasn't played a game since May 6.
"The next step is to carry out further tests [on Reyes] and to see his current status, before assuming anything," Mexico's national teams director Dennis te Kloese told reporters in Copenhagen after training.
"We'll have to speak to the medical department before giving a more formal report."
In the event of the versatile defender/midfielder Reyes not making the World Cup, Te Kloese confirmed that Pachuca midfielder Erick Gutierrez -- who is already with the squad in Denmark -- would be his replacement.
Former Denmark goalkeeper Peter Schmeichel visited the Mexico squad's training on Wednesday as El Tri prepares to face the Danes in Brondby Stadium in both teams' final tune-up before Russia 2018.