Roberto Martinez has confirmed receiving bids for left-back Maynor Figueroa, which he has described as insulting.
The Wigan manager has also launched a scathing attack on the agent of the Honduran, who he thinks is trying to engineer a move, with Sunderland keen to take him.
Martinez has claimed Figueroa's agent is stirring up the speculation, despite admitted the fact that bids have been lodged.
"In the window there is a lot of talk and speculation, and it is a great moment for the authorities to look into how much we need it," said Martinez after the 2-1 defeat at Blackburn.
"We come into this game and one of my players has been surrounded by a lot of speculation and stories about him going away.
"Unhappy is not the right word. I'm disgusted.
"The authorities should look into the necessity of the window and the agents who have this power and unhealthy control in the game, with the backing of a Premier League club, and that's disgusting.
"It gives the opportunity to certain agents to have a big say in the game. The power is given to the wrong people.
"We've had two insulting bids for the player, but he is not for sale. I've made it clear we're not going to sell any of our best players.
"If we're going to sell a player it will be at the right time for the club to collect some money and to reinvest for the next level."