England were unfortunate to lose to New Zealand on the Duckworth-Lewis scoring method in Saturday's rain-ruined Super 10 match and the 2010 champions need to beat in-form Sri Lanka in Chittagong to remain in control of their destiny in the tournament.
They face a difficult task against the Group One leaders, after Angelo Mathews, Malinga and Mendis helped dismiss the Netherlands for a record-low total of 39 in Monday's nine-wicket romp over the tournament minnows. Bopara attributed the Dutch rout to their inexperience and said England were better prepared for Malinga, whose sling-shot action makes him difficult to read, and the mystery spin bowling of Mendis.
"I didn't expect them to be bowled out for 39 but Sri Lanka are tough customers, especially if you haven't played them before," Bopara said. "I don't think the Netherlands have played much against Sri Lanka but we've seen a lot of their cricketers.
"We've played against Malinga quite a bit, we've played Mendis, so we'll be a little bit more prepared."
Having beaten both South Africa and the Netherlands, Sri Lanka can afford to relax a little in Chittagong but Bopara knows England have no such luxury. "It is a must-win game for us. I don't think we know about the mathematical side of it; we have to win," he said.
"Winning against Sri Lanka would be a big thing for us, a big confidence boost and that's how we're looking at it. The belief is still high in this team. We've done a lot of good things in the last few games, although we haven't won a lot of games the boys are getting better at their skills."
Compared to other line-ups such as Australia and the West Indies, England are low on batting firepower and Bopara is aware that coming out at number six, he will be relied on to clear the ropes early in his innings.
"I have been lying in my bed at times and thought: why don't I just hit the first ball for six?" he said.
"It is a mental approach, definitely. But I have thought about it. I might do it tomorrow, if I get a bat."