The tournament favorites started the World Cup with a comprehensive 104-run win against South Africa before they collapsed against Pakistan at Trent Bridge.
However, Morgan said England would not change their aggressive approach which brought them to the top of ODI rankings.
"All we talked about is sticking to what we do well, looking at our strengths," he said in his pre-match press conference in the Welsh capital on Friday.
"Previous to the tournament starting we talked about losing games -- how would we react? What would we counter that with?
"Everything comes back to focusing on ourselves, how we win games of cricket and get the best out of ourselves."
England had brought in Mark Wood against Pakistan at Trent Bridge, following West Indies’ bumper warfare against the same opposition.
Conditions are expected to be more conducive for quick bowlers in Cardiff, meaning Plunkett come back into the playing XI in place of a spinner.
"We'll see another day where the wicket is under covers," Morgan said. "The pitches here have been a bit greener and more seamer-friendly so that's a potential (option), yeah."
Morgan said their contest against Bangladesh would be a tough one and they won’t underestimate them at any cost.
"It is going to be a difficult game, they're a good side. I think people underestimate them but we certainly don't," Morgan said.
"Their senior players especially have played a lot of games, more so than our senior players. They are a threat but hopefully we can play well and overcome it.”