The Football Association will speak to both Manchester clubs to try to avoid any flashpoints during next week's Carling Cup semi-final decider at Old Trafford.
It is expected the FA will officially confirm Gary Neville will face no sanction over his one-fingered gesture to Carlos Tevez during Tuesday's first-leg, when City won 2-1.
Although there are photographs showing Neville's reaction, as Tevez is not in the frame and the incident was not captured on TV, it is virtually impossible for the FA to prove what happened and the incident itself was regarded as minor.
Nevertheless, the FA acknowledge the simmering tension between the two sides could lead to an escalation of the problem next week, when the red and blue halves of Manchester face each other once more to decide who will face Aston Villa at Wembley on February 28.
Although the desire for cool heads will be kept informal, the FA hope the two clubs heed their message given the huge number of people who will be watching a match which has captured attention far beyond the city itself.
However, Tevez has no intention of toning down his celebrations should he score again against his old club, or City win.
The Argentina star has admitted his ears-cupped reaction to the second goal was directed at the United hierarchy, including chief executive David Gill, but that he had also been unhappy that Neville stated at the weekend the Old Trafford club were right not to pay him the money he wanted to stay.
"I thought Gary Neville had been disrespectful by talking about me like that," Tevez told the Daily Mail.
"He cannot possibly know the full story of what happened at Old Trafford. I was honourable at all times and I think it was wrong of him to talk about another footballer in that way.
"For me, to celebrate in front of him was not malicious. It was just banter. That is what the game is all about. I didn't see if he did anything back.
"I wear my heart on my sleeve but I also have utmost respect for other players, especially the ones at United.
"I have won five trophies at that club and made a big contribution. I had thought and hoped that they would show respect back.
"But people get carried away by the celebrations. These things get the crowd going and help the team. I expected Manchester United supporters to give me a hard time. I hoped they wouldn't but I thought they would.
"Should I score in the second game next week then I will celebrate with equal enthusiasm and I am sure - if Gary does - he will do the same."Reuse content