Ronaldo has declared himself fully fit for Monday's Group G clash with fellow European heavyweights Portugal after knee and thigh injuries.
"The problems are all in the past," he told a pre-match press conference in Salvador.
"If I feel something, and I am sure I won't feel anything during the game, I will not risk my career. I come first and not football.
"Since the start of my career there's not been one single day in which I've played without pain. It's just the burden of my work.
"I'm ready, I'm feeling well. I don't have anything to prove. One player is not a team, I can't carry the whole team on my back.
"I don't think I have to show anyone anything.
"Look at my statistics and CV - I have nothing to prove.
"My career has been great so far and I just want to continue."
Germany coach Joachim Low has given his side a clean bill of health.
Midfielder Bastian Schweinsteiger, who went to hospital for a scan on Saturday, and goalkeeper Manuel Neuer, who missed Germany's final two warm-up friendlies and a training camp last month due to a shoulder injury, are both ready to start.
"I think we can go into the tournament positively - all of the players have come through our final training session fully and so we can assume that all of them will be 100 per cent ready to play," Low told a press conference.
"I think both Andre Schurrle and Lukas Podolski could start (in place of Maro Reus who was ruled out of the tournament through injury).
"You can see that Schurrle has benefited from his year in the Premier League while Podolski is just oozing energy.
"We've got plenty of good options."
Captain Philipp Lahm will start as one of two defensive midfielders with Champions League winner Sami Khedira favourite to partner him.