Why was Paul content to play backup goalie?

Paul originally tries out for the Lake Windsor Middle School soccer team, but isn't picked due to his visual impairment. The terms of the school's insurance policy will be voided if they allow someone with Paul's disabilities to participate in sports. Not surprisingly, Paul is pretty upset at the news, especially as he wants to prove to everyone that his eyesight is not as bad as they think it is.
So when Paul moves to a new school, Tangerine Middle, he is pleasantly surprised when Ms. Bright, the coach, tells him he can be backup goalie for the soccer team. Most people might not be too pleased with such a lowly position on the team, but Paul sees this as his big break, a chance to make his mark and show everyone what he can do. He is also very glad that someone has finally seen past his disability to recognize his talent.