Club Brugge manager Michel Preud'homme has told fans not to underestimate Leicester City before Wednesday's Champions League Group G game.
The Belgian club expect 9,000 of the 29,000 seats at Jan Breydel Stadium to be empty for the Foxes' European debut.
"Maybe [fans] have the wrong perception of the quality of the opponent," said Preud'homme, whose side play their first group-stage game for a decade.
"The Belgium press says it's not a big team but I say they are."
Premier League champions Leicester have sold out their ticket allocation for the match (19:45 BST).
"If we get Roma, everyone will say 'Roma, we want to see it' but they might eliminate us," added Preud'homme, whose team are 10th in the domestic league after three defeats in six games.