Keylor Navas was on the bench as Real Madrid drew 2-2 with Villarreal on Sunday in what is set to be his last involvement with the club.
The Costa Rican goalkeeper has worn the club's shirt for the last time and is set to complete a move to Paris Saint-Germain on Monday.
Navas did not return to Madrid with the rest of the squad, instead heading to Paris to complete a deadline day transfer to the French champions.
Once he's passed a medical, PSG are expected to confirm a €15 million deal for the stopper, with Areola moving the other way on a season-long loan.
PSG have also signed goalkeeper Sergio Rico from Sevilla, who will be the backup to Navas in Paris this coming season.
Navas has enjoyed great success at the Santiago Bernabeu, winning multiple Champions Leagues, but his place has been taken by Thibaut Courtois.