Those players were called up for World Cup duty but didn’t travel after Premier League teams objected to them going to South American nations which are red-listed by the British government and require 10 days of mandatory hotel quarantine on their return.

However Brazil, Chile, Mexico and Paraguay agreed to waive their right to trigger a FIFA regulation that would have compelled them to play for their respective countries.
Had they gone they would have to spend manadatory covid quaratine time and miss training etc when they returned.