FC Twente chairman Joop Munsterman says Fulham will need to return with a much increased offer for Costa Rican winger Bryan Ruiz after a bid of £7.5m was turned down.
Munsterman told Dutch newspaper Die Telegraaf:
We could not take the offer seriously. It was too low.
Twente are prepared to hold for the £13.75m release clause that would allow the 26 year-old to leave. Tottenham have also been linked with Ruiz, but Harry Redknapp has played down his interest this week.