Coach Luiz Felipe Scolari announced on Friday that Porto midfielder Maniche, who fell out with him after a 3-0 home defeat by Spain last year, will start the game at the expense of Benfica's Armando Petit.
The Brazilian, who led his own country to their fifth world title in South Korea and Japan two years ago, said Maniche's long-range shooting and willingness to go forward had earned him a place in the side.
Scolari had been expected to field the team that started last week's 4-1 friendly win over Lithuania, where Petit lined up alongside Costinha in front of the defence.
Scolari has insisted he is under just as much pressure as he was two years ago, when 170 million Brazilians were closely scrutinising his every move and demanding nothing less than victory.
"It's the same," Scolari said. "You can ask the same thing to the coach of England or the coach of Latvia and you'll get the same answer. The first thing they want is victory."
Scolari also made a last-gasp change to his Brazil side on the eve of their World Cup opening match against Turkey, replacing Kleberson with Juninho in a move which gave the team
The South Americans cruised through their first-round group, winning all three games and scoring 11 goals.
Greek central defender Nikos Dabizas, a regular as his team finished top of their qualifying group ahead of Spain, will miss the game with a back injury, and striker Demis Nikolaidis is doubtful with a nagging calf muscle injury.
Otto Rehhagel, the German coach of Greece, has described the match as his the most important in 20 years for his side.
"It's great that after such a long time there is finally another Greek team in the European Championship, and on top of that we are playing the strongly fancied hosts in the opening game," Rehhagel said.
Probable teams:
Portugal (4-4-2): 1-Ricardo; 2-Paulo Ferreira, 4-Jorge Andrade, 5-Fernando Couto, 3-Rui Jorge; 6-Costinha, 18-Maniche, 7-Luis Figo, 10-Rui Costa; 9-Pauleta, 11-Simao Sabrosa.
Greece (4-4-2): 1-Antonis Nikopolidis; 14-Takis Fyssas, 5-Traianos Dellas, 19-Michalis Kapsis, 2-Yourkas Seitaridis; 10-Vassilis Tsartas, 20-Giorgos Karagounis, 7-Theodoros Zagorakis, 8-Stelios Giannakopoulos; 11-Demis Nikolaidis, 9-Angelos Haristeas.
Referee: Pierluigi Collina (Italy)
Linesmen: Marco Ivaldi, Narciso Pisacreta.