Wigan Athletic boss Chris Hutching wants £6 million for left-back Leighton Baines.
"We turned down a bid from Everton of £4million and a player, who they rate at around £2million," he told BBC Radio Five Live.
"I have a very good relationship with Leighton and we'd like him to stay but we can't stop speculation or other clubs making offers."
But the former Bradford boss also confirmed that if the England Under-21 international was to leave, the Latics would be looking for a similar fee to the one agreed with the Black Cats.
"It wouldn't be very good business if we took less than that, so we'll be looking for that," he said.