Doncaster Rovers assistant manager Richard O'Kelly insists that it will take an 'unbelievable offer' to prise Matthew Mills away from the club.
The defender has been linked with moves to Birmingham and Nottingham Forest over the summer but so far neither club have matched Rovers' valuation.
The 23-year-old played 45 games in all competitions last term and has shone since signing permanently for the Championship club last year from Manchester City.
O'Kelly states that Mills has been unfazed by the speculation regarding his future and is continuing to impress in training.
"Matt's been in training with us and has shown a great attitude towards our preparations for the new season and has been working extremely hard," he told skysports.com.
"Whatever happens away from the training ground is out of our hands really. If someone comes in with an unbelievable offer then you have to listen.
"But at this moment in time Matt's here working hard to be in contention for a place in Doncaster Rovers' starting line-up."
Out to impress
O'Kelly also revealed that the club had taken Barrow striker Jason Walker on trial after he impressed in a friendly against the two clubs last weekend.
"He showed some good things against us on Saturday. We felt that his movement was good and he looks hungry to prove himself in the game," he added.
"When you see people like that, at a club which we have a good relationship with, then there is no harm in having a better look at the lad.
"Both parties will take a good look at each other and weigh up whether they suit one another or not."