The Real Madrid star is unlikely to be risked unduly by coach Paulo Bento for Saturday's clash after picking up a thigh injury during the week.
The Seleccao captain picked up a minor thigh problem this week and is therefore not expected to play a significant part when his side face the team which beat his side in the final of Euro 2004 a decade ago.
Having beaten tournament host Portugal 2-1 in the opening game, Greece once again sprung a surprise in the Lisbon showpiece, securing a stunning 1-0 victory over the same opponent thanks to Angelos Charisteas' goal.
Greece also beat the Portuguese 2-1 in March 2008 in their only meeting since that famous victory 10 years ago, courtesy of a Giorgos Karagounis brace.
Portugal, however, will fancy its chances of gaining a morale-boosting victory at Estadio Nacional on Saturday as the team gears up for the upcoming World Cup finals in Brazil.
Having beaten Sweden in a playoff to seal a spot in the tournament, Paulo Bento's side hammered Cameroon 5-1 in March in a landmark fixture for Ronaldo.
The Real Madrid forward became his country's all-time leading scorer by finding the back of the net twice against the African nation to take his tally to 49 goals in 110 appearances.
Portugal has won four of its last five games and will be eager to maintain that momentum ahead of subsequent matches against Mexico and Republic of Ireland.
The side will need to hit the ground running when the finals start next month, as a well-backed Germany side is the opponent in Portugal's Group G opener at Arena Fonte Nova in Salvador on June 16.
The United States and Ghana are Portugal's other opponents in the group phase.
Coach Fernando Santos, who will step down after the World Cup, guided Greece to the World Cup finals for only the third time courtesy of a playoff win over Romania.
Portuguese Santos' immediate focus will be on getting one over his homeland and he will be expecting Kostas Mitroglou to justify his selection in his 23-man squad.
Mitroglou was troubled by injury and a lack of form after joining Fulham in January, but the striker got the nod to board the plane to Brazil regardless having fired 17 goals in 19 games for Olympiakos prior to his Premier League switch.
If the 26-year-old can recapture his form then Greece will be in with a great chance of progressing from Group C - which comprises of Japan, Colombia and Cote d'Ivoire.