Former England defender Gareth Southgate feels it would be a "big mistake" were Roy Hodgson's squad to underestimate the challenge posed by Sweden in Kiev on Friday night.
England produced a composed tactical display as they held France to a 1-1 draw in Monday's opening Group D encounter. But Sweden have not lost to England in a competitive fixture - a sequence of seven World Cup and European Championship encounters.
Southgate said complacency "would be a big mistake", adding: "You have to respect every opponent you come up against. Sweden have some very, very good players and, in Zlatan Ibrahimovic, they have an outstanding forward. When you get to this level at a tournament you never play against a side who are not capable of hurting you."
Southgate, who won 57 caps and played in two European Championships as well as the 1998 World Cup, managed the Carlsberg Pub Cup winners in their game against a team of European legends at the Carlsberg Fancamp in Warsaw on Thursday.
He said: "You always need to be prepared and can never take the opponents or any result for granted, as we have seen with Holland against Denmark and some of the other matches. You really have to put to one side what was done against the French, when the expectation was different.
"The difficult thing now is people expect the next two games to be easier and I don't necessarily think that will be the case. Sweden have to win against us and we saw how powerful the home support is going to be for Ukraine.
"If we draw tomorrow then we will still be in contention, but I think we need to beat them."
It remains to be seen what, if any, tactical switches Hodgson makes for Friday's game, when England will again be without main striker Wayne Rooney, who serves out his two-game suspension.
Southgate believes the Swedes will pose another test for the new manager to solve.
"We would expect to have a bit more of the ball against Sweden and the threat from them will be a slightly different one from France, so it will be interesting to see how we approach the game," he said.