Hull have had a bid rejected for unsettled Cardiff striker Ross McCormack.
The Tigers have been heavily linked with the 22-year-old Scot in recent weeks.
Cardiff are thought to value McCormack, who recently signed a new four-year contract, at around £4million.
Hull manager Phil Brown told the Hull Daily Mail: "We've made our move, we've put a bid in for Ross McCormack but the bid has been rejected.
"Hopefully we can agree terms between the two clubs and the player still but we won't raise what we've bid because we think it's a good offer."
McCormack was quoted earlier this week saying he feared Cardiff were pricing him out of a move to a Premier League club but later backtracked on the remarks.
Hull are keen to add more firepower to their squad ahead of the start of the Barclays Premier League season on August 15.
Former Motherwell striker McCormack caught the eye last season with 21 goals in 38 Coca-Cola Championship appearances for the Bluebirds.
Hull yesterday completed their first signings of the summer by bringing in midfielder Seyi Olofinjana from Stoke and Villarreal striker Jozy Altidore on loan.
Former Wigan striker Henri Camara is currently on trial with the Tigers while a bid for defender Habib Beye has been accepted by Newcastle.