Sweden coach Lars Lagerback has admitted David Healy poses the biggest threat to his side in this week's Euro 2008 qualifier.
Northern Ireland play host to Group D leaders Sweden in a top-of-the-table clash on Wednesday night.
Healy goes into the game in fine fettle after netting a hat-trick in Saturday's win over Liechtenstein and Lagerback is wary of the threat posed by the Leeds man.
"Healy is always running and shoots from every angle," said Lagerback. "He is very effective. If they can, Northern Ireland play directly at him.
"It's important that Olof (Mellberg) and the boys watch him and do not let him in behind the defensive line.
"But they have been good at controlling fast players in earlier matches."