The Scot is still furious with the performance of referee Martin Atkinson after he showed Toffees midfielder Jack Rodwell a red card – which was later rescinded – in Everton's defeat to Liverpool two weeks ago.
Atkinson avoided a short-term demotion to the lower leagues this week as punishment, while the Everton boss has now suggested that poor referees are threatening to damage the game.
"They tell us the image of the game is vitally important to the Premier League - the conduct of the players, the conduct of the managers, to make sure the image is right," he said.
"But I think at the moment it is the decisions of the referees that are giving the Premier League a difficult image because people are saying the decisions were not good.
"The image of the game is not being tarred by the players. The players are enhancing the image with their quality. The Premier League has some of the best managers in the world. But the Premier League will need to see if they think they are getting the same from the people who run the referees."
Following the loss to Liverpool, Everton are currently 13th in the league table on seven points.