Vryzas spent the first six games of Greece's qualifying campaign looking on from outside of the squad but returned in style by netting the only goal of the game as they beat Armenia in September.
He kept his place for the following qualifier against Northern Ireland but must be an outsider to claim a starting spot in Portugal with the likes of Angelos Charisteas and Demis Nikolaidis around.
The former PAOK Salonika and Perugia man, who now plays his club football for Fiorentina, gives Otto Rehhagel options up front.