McCall is aware that some of his players may need to move in order to gain a bigger salary but he feels that they would be careless to believe they can simply go on and make it with English clubs.
"We are already identifying people for some positions. You're not doing your job correctly if you're not," he said.
"No one has said to me they are definitely going to leave, but I'm sure we'll get a few indicators next month.
"I've got to be realistic. Darren is a top keeper who could easily play in the Championship. Financially, that would be a lot better for him and it might also help his international prospects.
"If I could persuade him to sign a new deal, I would. Although he hasn't said he's going, I expect him to move on.
"I can see it from a player's point of view, but there are examples of people leaving here and not always progressing as they would like.
"And John Sutton moved to a bigger club, then got farmed out to Australia.
"There are players going off to countries where you can't believe they play football just to earn a wage.
"But the good players have decisions to make."