Rooney's best position in the side has been the subject of intense debate in recent weeks, with his versatility seeing him deployed on the left-hand side of the attack for the bulk of England's warm-up matches.
Former Manchester United team-mate Paul Scholes even questioned whether Rooney - a mainstay of the England side since making his debut as a 17-year-old in 2003 - should even be regarded as an automatic selection.
The 28-year-old has said in the past he favours a more central role but with Daniel Sturridge and Rickie Lambert preferred to lead the attack in recent friendly matches, Rooney has accepted he may need to adapt.
"I have played there quite a lot in my career," said Rooney.
"I have played left and right, more so on the left. The manager asked me to play there and I have no problem doing it.
"I am not going to stop playing for England because I was moved out on to the left wing, am I? I am happy to play for England where I am needed."
Rooney said he was relieved to finally be heading to a World Cup without any major fitness issues, after the lingering effects of injury undermined his hopes of making an impact at his previous two tournaments.
Rushing back from a metatarsal problem in 2006 and an ankle injury in 2010 saw him head into the tournaments lacking match fitness and failing to get close to the impact he made at Euro 2004 as an 18-year-old.
Rooney did miss the end of the domestic season with a minor groin problem, but worked with a fitness coach in Portugal during his week off before the start of England's first training camp.
"I am happy going to these finals feeling fit," said Rooney, who started all three of England's recent friendlies.
"I have played in every training session and I am excited. I am ready to play, ready to enjoy it and hopefully ready to do well.
"I feel good and obviously playing against Ecuador (and the other matches) will have helped me as well after missing the games at the end of the season.
"I have trained hard and I feel good and am ready to play."