Everton are understood to have officially complained to the Premier League regarding recent refereeing decisions.
The club were left frustrated during the recent 1-0 loss against Manchester City as the Toffees believe they should have had a penalty when Rodri appeared to handle the ball in the box.
Ultimately, the decision did not go in their favour, with the defeat leaving Everton just one point above the relegation zone as Frank Lampard publicly questioned the officiating after the match.
According to Sky Sports News, the Toffees are 'absolutely incandescent' about the recent calls that have gone against them, most notably from the past weekend, and they are demanding an apology at the least.
First-team coach Ashley Cole ended up being yellow-carded after the game due to his complaints to referee Paul Tierney, adding to the situation.
Everton are back in action on Thursday night in the FA Cup against Boreham Wood.