Chile coach Claudio Borghi will allow Sanchez to travel to finalise a possible move as they do not want to be liable in the event of injury.
If he signs for Barca without travelling and is then injured in the tournament then Chile could be liable for a whopping £27.8million bill.
Chile are eager to avoid a potentially messy financial scenario by allowing the coveted talent to link up with Barca once the terms of the deal are agreed.
"It's a very complicated matter," Borghi told Chilevision. "If we don't allow him to travel, and the sale goes through, we would be accountable for $45million in the event of anything happening to him.
"It's very simple. As soon as the confirmation of his transfer comes through, he will have the authorisation (to travel).
"If (the transfer) happens in the middle of the Copa America, obviously not, but we have time and we know we cannot be responsible for that amount of money, so the ideal situation would be for him to travel and sign when the deal is confirmed."