Wigan manager Roberto Martinez insists the days are over when the club could only attract players by being a stepping stone to more illustrious rivals.
Martinez is determined to resist any advances but he feels Wigan are a big enough draw on their own. "I do see a change," Martinez told www.wiganlatics.co.uk. "It is something that we had to do in the past. We needed to embrace it."
He added: "The players were coming into a new league and they knew they could develop and move on. We had the benefit of getting outstanding talent. They needed to adapt. I don't think we are in that situation now.
"It was important that we changed it. The players need to know what it means to represent Wigan and, slowly, get them to achieve more at our football club."
Martinez has already spoken so highly of McCarthy, it is impossible to imagine he will not leave at some point.
The crucial factor is it will be at a time of Wigan's choosing.
"When a team like Manchester United loses players because they want to try something different, you realise it is part of the modern game," said Martinez.
"I always feel it is not about losing players, it is about how you are going to replace them.
"It has to be at the right time for the club. And also the right price. And we need to create a culture where we can keep our assets for a little bit longer."