Manchester City manager Pep Guardiola offered a sarcastic response when asked about referee Martin Atkinson's failure to award his side a penalty against Manchester United.
The Citizens had a strong appeal turned down late on in the 3-2 defeat when Ashley Young went over the top of the ball and caught Sergio Aguero on the shin.
Guardiola has now reviewed the incident but was unwilling to say too much when further probed two days on, despite the decision possibly costing his side at least a point from the match.
Speaking to reporters ahead of Tuesday night's Champions League tie with Liverpool, the Catalan coach simply said: "He's diving!"
Aguero is expected to feature against Liverpool at the Etihad Stadium, having played the final 14 minutes of the derby defeat to United.