Manchester United stary Wayne Rooney admits he is yet to prove himself a world class player. But ahead of the clash with Algeria in Cape Town on Friday the England striker is feeling "sharp and hungry". Rooney admits there is room for improvement in his own performance following England's 1-1 draw with the United States in their opening World Cup game. He is keen to live up to his reputation as one of the most lethal forwards in world football after a disappointing 2006 tournament in Germany when he lacked sharpness following a broken foot. The Reds star also had an injury-hit end to the club season following an ankle injury suffered against Bayern Munich in the Champions League. But he is adamant he is now firing on all cylinders. Rooney said: "This is a great opportunity for England and for me to prove myself at the world level. If I don't do that, I'd be disappointed. "I haven't proved myself on the world stage yet. The last World Cup was a disappointment for me. "I'm looking to do well in this one and try to prove myself on the world stage. "I've sort of forgotten about the last World Cup now and I've moved on. "What drives me on is trying to win for England and trying to do well at world level. That's a great driving force for any player." Rooney has managed to put the injury against Bayern behind him and is looking to step up a gear against Algeria. He said: "I got the injury against Munich and, once you get injured, you lose your match fitness and sharpness. "It was difficult to play as well as I wanted. But I'm not focused on that. I'm focused on England. "When I was playing well and scoring this season, in training I was sharp and hungry. That's how I feel at the minute. "At the training camp in Austria I had a few niggles and in training I held myself back. "But since we've come over to South Africa I've felt sharp and been flat out in training. "That's important for me to do that to get my form back in the games." Rooney admitted: "I watched the USA game again that night. I saw where I could do better, where I should have been, how to improve my positions. "It was quite interesting to watch. Everyone can have a quiet game. We need nine out of the 11 players on song to win games. "There were moments when I did some good things against the USA and moments when I would have liked to get on the ball more. "There were glimpses. But personally I know I can play better and hope to put that right." Is Rooney genuinely world class? Have your say.