But even at that tender age, he realised what he was capable of.
"At the time, at 16, I remember looking around the Everton first team and knowing I was the best player. I felt that.
"I knew deep down that for me to further my career I would have to go somewhere else."
After two seasons in the Everton first team, Rooney moved to Manchester United as an 18-year-old in 2004.
"I always felt I was good enough and I wanted that challenge," he says.
"Having grown up watching the Premier League, I know a lot of people talk about the Champions League and how important it is to win that but the first Premier League title was really special."
While Rooney went on to score 208 Premier League goals in total, second only to the record 260 of Shearer, it took him time to adopt a striker's mentality.
"I played as a striker on my own [in 2009/10] and scored 34 goals," he says.
"I remember coming off the pitch after scoring one or two and saying, 'I just don’t feel I played that well or was involved in the game.'
"It was strange. That was really the time when I learned to be more patient and to wait for my opportunities.
"I always wanted to try to be involved in the game. But I knew, as a striker, if you wanted to score more goals you'd have to do more of your work inside the box."
That scoring instinct remains as he has become a star for DC United in MLS, scoring 10 goals from 18 appearances since his January move, lifting his team into play-off contention.