The striker, still just 21, is included in the squad to play in Sweden tonight and sees it as a major opportunity to impress coach Sven-Goran Eriksson.
"The manager had a meeting with us and said the door is open for everyone," said Jermain. "All I'm here to do is keep my head down and keep on doing what I'm doing. It's up to me to take my chance.
"Hopefully if I keep on working hard you never know what will happen in the summer.
"I have been encouraged by other young players like Wayne Rooney and Jermaine Jenas and Joe Cole. If I keep working hard and scoring goals it helps - and you never know what can happen."
The match against Sweden is a major opportunity for newly-picked players such as Defoe, Shaun Wright-Phillips and Robert Green to shine. And there is no chance of them taking it lightly.
"We're looking forward to it. No game is a friendly. It's an important game for me and I'm sure it's an important game for all the other players," added Jermain on thefa.com.
"I've been given a chance and I want to try and grab it with both hands.
"There's loads of players in the squad with lots of caps and experience and I'm sure they will help me along as well.
"But there's also a lot of young players from the Under-21 team and hopefully we can do really well - and as I say you never know what will happen in the summer."
Jermain Defoe admits he is dreaming of playing in Euro 2004 after being called up to the England squad for the first time.