Question marks over the fitness of the FIFA Ballon d'Or holder have dominated Portugal's build-up to the tournament.
The Real Madrid forward has been plagued by thigh and knee problems for several weeks, but is expected to feature from the start against Germany in a game both sides can ill afford to lose.
With Ghana and the United States representing potentially tricky future opposition, the European sides in Group G know an early defeat would severely dent their respective hopes of making the last 16.
Portugal will therefore be desperate for Ronaldo, their captain and undoubted star man, to lead from the front as they face a team that has finished third in the last two World Cups.
Midfielder William Carvalho, among those to have delivered positive updates on Ronaldo's progress in recent days, believes Portugal are capable of impressing against Joachim Low's men.
"During the training sessions we talk about how we will play with each other, but we simply have our strategy and I am sure that in the first match you will like how we play," said Carvalho in a press conference.
Germany have been forced to cope with injury issues of their own ahead of the tournament.
Marco Reus was ruled out of the World Cup last week after tearing ankle ligaments in a friendly against Armenia, while Bayern Munich trio Manuel Neuer, Philipp Lahm and Bastian Schweinsteiger have all seen their preparations hampered by minor setbacks.
Nevertheless, Low's side are fancied by many to make the latter stages of a fifth successive major tournament.
In addition to their third-place World Cup finishes in 2006 and 2010, Germany also reached the final of UEFA Euro 2008 - before ultimately losing out to Spain - and the last four of Euro 2012.
Germany kicked off the latter competition with a 1-0 victory over Portugal and many of the players involved in that game are set to feature again in Salvador.
However, the match-winner two years ago, Mario Gomez, was left out of Low's 23-man squad after a season wrecked by a serious knee injury.
As a result, Miroslav Klose is the only out-and-out striker in Germany's party and the veteran Lazio man can equal a notable record by finding the net against Portugal.
Klose currently boasts 14 World Cup goals, one shy of the mark set by legendary Brazil striker Ronaldo.
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