UEFA have charged Manchester City boss Pep Guardiola with two disciplinary offences after he was sent to the stands during Tuesday's 2-1 defeat to Liverpool.
Liverpool also face punishment for their fans throwing objects and setting off fireworks after disciplinary proceedings were opened by European football's governing body.
Guardiola faces a first charge for his protests to the decision to rule out Leroy Sane's effort for offside late in the first half - despite the ball having come to him off a Liverpool player - which led to him being banished from the touchline.
The second breach was for communicating with the bench after being sent to the stands - under article 69 of UEFA regulations, this would have been forbidden.
Guardiola entered the field of play at the half-time whistle to express his dismay at Mateu Lahoz's decision to rule out the goal - which could have made it 2-0 to City - leading to his expulsion from the technical area.
He was forced to watch the second half from the stands as his side crashed out of Europe's elite competition at the quarter-final stage for a second consecutive season - losing 5-1 on aggregate.
The case will be dealt with by the UEFA Control, Ethics and Disciplinary Body on May 31.