Portsmouth make their UEFA Cup debut on Thursday with a first-round clash at home to Vitoria SC.
And England striker Defoe believes he can keep banging the goals in for Pompey, provided they don't take their foot off the gas against the little-known Portuguese side.
He said: "Vitoria finished third in their domestic league so it’s going to be a tough test.
“I’m really looking forward to travelling to play some of the best sides in Europe but we’ve just got to take it one game at a time and keep working hard as a team.
“I’m always going to get chances because I’m playing alongside quality players. When I do get the chances, I’ve got to take them.
“If I’m playing games and feeling sharp, then I’ll score goals.
“I want to improve with every game and I just work hard and try to get my goals.”