The Danes top Group 1 with 13 points, ahead of Hungary on goal difference, while Sweden are seven points behind their Scandinavian rivals with a game in hand. Both sides are unbeaten though, and Lagerback is aware his men need to extend that record if they are to maintain their challenge for a top-two finish.
"We feel as if we're well prepared for Denmark and how they'll play," said the Sweden boss. "We know they like to move quickly and they also use wingers, which means we'll have to play a little wider than we normally do in our defensive play.
"You could say we have to win this match if we want to be in with a chance of winning the group. A draw would also count, but if we lose we're definitely looking at second place at best."
Denmark striker Nicklas Bendtner is also aware there is more than regional pride at stake for Morten Olsen's side. "A draw is never a good result. I want to win," said the Arsenal man. "The Swedes are strong. They've only conceded one goal up to now, but on the other hand they've only scored twice. They have players who can make a difference though."
Per Kroldrup (knee) has been forced to withdraw from Olsen's squad with Thomas Augustinussen taking his place. Michael Gravgaard is on standby to replace Daniel Agger if the Liverpool defender fails to recover from a back injury.
Albania and Portugal will also be aiming to close a seven-point gap on the group leaders when they clash in Tirana. The Portuguese have two games in hand over their opponents, but three successive goalless draws have knocked their qualifying campaign off track.
Coach Carlos Queiroz knows their lack of scoring is a problem which needs addressing quickly. "Finishing is an important part of the game," he said. "We will never play well if our finishing is poor.
"We have to dominate all areas of the match, including up front where we need to get the ball in our opponents' net often enough to win the three points. The team are well though, mentally, physically and tactically and we are full of enthusiasm and confidence."