Birmingham boss Steve Bruce says Leicester will have to increase their bid to prise Stephen Clemence and DJ Campbell away from St Andrews.
Clemence (left) and Campbell are wanted by Leicester
The Blues' boss confirmed a bid had been received for defender Clemence, 29, but Leicester also want striker Campbell, 25, included in the deal.
Bruce told Blues website: "There was a bid which has not been accepted.
"They've also tried to put DJ into the equation, but the clubs are still talking and it's ongoing."
But Bruce admitted that Clemence - last season's player of the year - would be leaving St Andrews.
He added: "Stephen is close to a move, but we'll see what happens.
"It's a tough one for me with Clem, he wants to play football, but I now cannot guarantee him that he will be my first choice.
"So I have to be fair to him for what he has done the last past five years.
"I will never get a better pro or a nicer person or a better lad, but Leicester can give him three or four years and I'm not going to deny him that opportunity."
A Campbell move to Leicester would bring a reunion with Martin Allen, who managed the striker at Brentford and sold him to Birmingham in February 2006 for £500,000.