Manchester United manager Jose Mourinho has hinted he believes Pep Guardiola received preferential treatment in avoiding being sent to the stands on Wednesday.
Guardiola, the Manchester City manager, ran onto the pitch to celebrate Raheem Sterling's late winner as his team beat Southampton 2-1 to remain eight points clear of United at the top of the Premier League.
He was then seen in animated conversation with Nathan Redmond after the final whistle, appearing to remonstrate with the Southampton winger.
Redmond has since released a statement saying that Guardiola was "only very complimentary and positive" during the exchange, although the Football Association has asked the Spaniard to explain his actions.
However, the fact that Guardiola received no punishment at the time for entering the field of play angered Mourinho, who was sent to the stands during his team's 1-0 win at Southampton in September after stepping onto the pitch.
Mourinho did not receive a touchline ban over the incident, but feels that he was punished unfairly.
Asked if he was surprised that Guardiola was not sent to the stands, Mourinho said: "Surprised? No. Not surprised."
Pushed to elaborate, Mourinho indicated to journalists that he would get into trouble with the football authorities if he said what he actually thought.
He said: "No. No. No. No. You are asking me one question, if I am surprised. I say I am not surprised.
"The second question is nothing. It's another one. I can't answer to the second question.
"You know, if you are my friends, don't ask me the question, because you know I get into trouble, so no."
Mourinho, meanwhile, has defended striker Romelu Lukaku, suggesting that the Belgium international will soon rediscover his scoring form.
- Criticism -
Lukaku scored 11 goals in his first 10 appearances for United after joining from Everton in July, but has scored just once in 11 games for the club since.
Mourinho suggested at the end of October that the striker was receiving unfair criticism from the club's supporters.
He said then that Lukaku should be untouchable because his all-round contribution on the pitch was so important.
The manager has now indicated that he retains full confidence in the forward, who is set to face England in the World Cup in Russia next year after they were drawn in Belgium's group.
"He is going to score soon, no problem. He is going to score soon," he added.
"If it's Saturday, Tuesday, next week, I don't know but he is going to score soon. No problem at all. No problem at all.
"For me the most important thing is teamwork and he is second to none in giving everything he has to the team."
Mourinho refused to comment when asked about the possibility of signing Arsenal midfielder Mesut Ozil, who is out of contract at the end of the season, and who has been widely linked with a move to Old Trafford.
The United manager, though, is not surprised that Ozil has got so close to the end of his Arsenal contract without agreeing another one.
"That's football," he said. "There are other important players in Europe in other teams that they finish their contracts.
"Sometimes players decide to go in this direction, which is the right that they have.
"They gamble, because you know, imagine one of these players has a big knee injury, if one of these players has one of these injuries, probably next season, he is without a club.
"Players have the right to do that and I don't blame the clubs because the clubs, they try."