Denmark head coach Age Hareide has conceded that William Kvist could miss the rest of the World Cup with the injury that he picked up in Sunday's 1-0 win over Peru.

Yussuf Poulsen scored the only goal of the match as Denmark opened their Group C campaign with a victory.

The three points might have come at a price for Denmark, however, with Hareide fearing that Copenhagen midfielder Kvist - stretchered off in the 36th minute - has suffered a fractured rib, which would end his tournament.

"We think it's a fractured rib – we'll have confirmation later on," Hareide told reporters. "If it's a fractured rib he's out for the rest of the World Cup for sure. We cannot replace a player at this point in the tournament so we'll be down to 22 if he is out."

Denmark's next group match is against Australia on Thursday afternoon.