Pep Guardiola has been charged with two counts of misconduct by UEFA following Manchester City's Champions League loss to Liverpool, the European governing body has announced.
The Manchester City manager was sent to the stands at half-time of Tuesday's game at the Etihad Stadium for complaining to referee Antonio Mateu Lahoz over a disallowed Leroy Sane goal.
The first charge relates to his exchange with Lahoz and the second concerns a potential breach of regulations which forbid dismissed managers from communicating with the bench.
UEFA has also charged Liverpool on two counts over the behaviour of their fans, for letting off fireworks and throwing objects.
The cases will be dealt with at a hearing on May 31. The Reds were already the subject of UEFA disciplinary proceedings after City's team bus was attacked by supporters outside Anfield ahead of the first leg last week.
Liverpool won the second leg 2-1 to claim a place in the semi-finals with a 5-1 aggregate success.
City were angered when Sane had his strike chalked off shortly before the interval for offside when replays showed the ball had been played to him by Liverpool's James Milner.
Protests continued after the half-time whistle with Guardiola entering the field and exchanging words with Lahoz.
He was ordered to watch the remainder of the game from the stands, from where he would not be allowed to communicate with the technical area under Article 69 of UEFA's regulations. After reviewing TV footage, UEFA believe there may have been a breach in this area.