Portugal is a strong candidate to host the Champions League final after Uefa did not gain guarantees of exemptions it wants to move the game to Wembley.
Uefa has decided it will be moved after Turkey was put on England's red travel list meaning fans cannot travel.
Portugal is on the green list so fans would be allowed to attend on 29 May.
The match could still be played at Wembley but it would require a major shift from the government, who have so far failed to reach an agreement with Uefa.
European football's governing body feels in Portugal it is going to be easier to gain access for sponsors and broadcasters, who would need to be compensated if they were unable to attend the game.