Middlesbrough boss Gareth Southgate admits he would be loath to lose Robert Huth, who is wanted by a number of Premier League clubs.
Skysports.com understands a clutch of sides are looking at Huth, but Stoke City have made a firm move for the German international defender.
Huth captained Boro, in the absence of Emanuel Pogatetz and Julio Arca, in their opening game of the season as they drew 0-0 with Sheffield United last Friday.
Southgate has long stated that, although some players were available to leave, he wanted to keep Huth and his central defensive colleague David Wheater.
But now Stoke have made their move, and with others ready to follow suit, Boro could find it hard to reject offers.
"I would rather not sell him but I know there are certain things we have to do as a football club," said Southgate.
"But Robert's approach is first class. Of course, it would be fantastic if he could go to the World Cup with Germany and a move might help him to do that.
"But he has been very realistic about it and has told me that he understands that for him to leave a club has to offer the type of money Middlesbrough want.
"Robert has the physical attributes for this division but he also has composure on the ball too.
"In addition, he has started to develop excellent leadership qualities. He has shown me his ability to be a leader over the summer and that's why I gave him the captaincy against United."
Boro are still waiting to finalise the departures of Afonso Alves and Tuncay Sanli.
Qatarian club Al-Ahli are locked in talks with Boro over Alves and that deal should be finalised this week, but Tuncay's future remains unclear with no firm bids, although Aston Villa and his former club Fenerbahce have been linked with a renewed interest.
Boro are known to be in the market for at least one more striker, likely in the target-man mould with Rob Hulse, Dave Kitson and Marlon Harewood all thought to be under consideration.
"We've got targets in mind if people do move on, yes," said Southgate. "But there are some positions where we could lose a player without a problem, while there are others where we are a bit light.
"At the same time, if we lost Tuncay and Alves, I wouldn't necessarily replace them with the same sort of forward. We'd need to bring in the sort of player who is suitable for the division we are in."