Erling Haaland and co were excellent as they knocked out five-time world champions Brazil to set up a quarter final against England.
According to Norwegian outlet Dagbladet, several members of the squad have been experiencing flu-like symptoms throughout the tournament.
Among those affected have been striker Jorgen Strand Larsen, who missed Norway’s first game due to illness, and Marcus Holmgren Pedersen, who was unavailable for the win over Brazil.
Manager Stale Solbakken, who himself has appeared under the weather during recent press, has confirmed that an illness has been circulating.
"We've had a few players who haven't been feeling well, but things are getting better," Solbakken said. "It's not ideal during a tournament, but we're managing the situation."