Defoe has been overlooked for the last few England squads by Fabio Capello and he does not want to miss out on next summer's finals in Poland and Ukraine after missing the 2006 World Cup.
"I won't lie, I am worried about not going to the European Championship. I want to give myself every chance," Defoe told the Mirror.
"It feels already a little bit like the 2005-06 season, when I scored a lot of goals but didn't start a lot of matches. I ended up not going to the World Cup and I don't want that to happen again.
"I believe that if I am playing, I have got a real chance of going to the Euros. But I'm going to bide my time.
"I'm 29. I know that the reason I have been left out of the last few England squads is that I have not been starting for my club.