Cristiano Ronaldo, the world player of the year, has declared himself fully fit to take on Germany in the much-anticipated Group G opener in Salvador.
Ronaldo has been nursed through a knee injury both by Real Madrid at the end of the club season and by Portugal in the build-up to Brazil 2014.
The 29-year-old appeared at a pre-match news conference to declare his readiness for the challenge.
He said: "I've been practising for many days and I am feeling well. There has not been a single moment when I have not played without pain in my career, It's just the burden of my work."I'm ready, I'm feeling well. I want to play and help the national team. If I'm not fit, I'll be the first to tell the coach.
"If I feel something, and I am sure I won't feel anything during the game, I will not risk my career."
Ronaldo's last competitive match was the Champions League final victory, and he admitted the World Cup is a fresh challenge.
He said: "My career has been fantastic so far and I just want to continue.
"I relish challenges, I want to do my best in whatever competition I'm in. It drives me to succeed at a tournament.
"Of course I want to win this championship but let's take it one step at a time."