During the presence of Viera in Olympiacos and specifically on 26 March 1975, he alongside his teammate, Giorgos Delikaris competed in with World XI match together with Pelé and Johan Cruyff.

With the intervention of his journalist friend Nikitas Gavalas, he visited a specialist doctor in Austria where he underwent a hernia operation to overcome the problem that was bothering him.

Returning fully recovered to Greece, he faced the indifference of the people of the team who, taking into account his advanced footballing age of 31 years and the burden of his health adventure, released him.

[4] Upon hearing of his release from Olympiacos, the manager of AEK Athens, František Fadrhonc saw in his face the ideal solution to complete the "yellow-black" midfield, he suggested to Loukas Barlos the acquisition of Viera.

Barlos, after getting the consent of the club's doctor and former president of the then HFF, Vasilis Chatzigiannis regarding the player's health, responded immediately and in the summer of 1977 Viera came to AEK.

Viera became the irreplaceable "link" that connected the defensive with the attacking function of the team sometimes enlisting the required toughness of the defender and sometimes displaying technical training of a rare virtuoso.