Fulham have been told to double their reported offer of five million euros (£4.37million) for winger Nacer Chadli by FC Twente chairman Joop Munsterman.
The 21-year-old has impressed for the Enschede club since joining from AGOVV last summer and scored in both recent Champions League clashes with Tottenham.
Such form has seen Chadli attract interest from across Europe, with Fulham reportedly lodging a bid for the Belgium international.
Cottagers boss Martin Jol has been vocal about his desire to bolster his attacking options and Munsterman claims the Dutchman is also interested in Costa Rican team-mate Bryan Ruiz, although he does not expect him to get very far.
"The offer for Chadli we consider a half bid, "he told Voetbal International. "And Bryan did not even want to join Fulham."