Blues boss Steve Bruce reluctantly admitted that the club had made an offer for the 19-year-old England Under-21 striker but the Welsh side had rejected their offer.
"It's never been my slant to say what we have and what we haven't done, but there has been a bid for the striker at Cardiff," Bruce told Sky Sports News.
"Unfortunately, it's been knocked back.
"I'm sure the representatives of both clubs will get together and see if there is a deal to be done."Debut Apps (+ sub) Goals Yellows Reds 02/10/2004 69 (10) 27 11 0 First App. Apps (+ sub) Goals Yellows Reds 06/08/2005 47 (0) 20 7 0 02/10/2004 22 (10) 7 4 0