Tevez described the United captain as an "idiot" and a "boot-licker" after he scored twice in the Carling Cup semi-final first leg 2-1 victory. The Argentinian's comments came following an incident on the touchline at Eastlands with Tevez making a gesture towards Neville, who was warming up. He responded by raising one finger.
Regarding Tevez's remarks, Mancini said: "I think these things can sometimes happen after a match. The players are tired and sometimes they do not think what they are saying. It is important that this matter is finished now as we need to focus on our next game."
Mancini confirmed Tevez will be rested for the FA Cup match against Scunthorpe on Sunday, so he is fresh for the second leg at Old Trafford on Wednesday.
The Italian boss does not believe Tevez's comments about Neville could provoke crowd trouble.
He added: "I hope not. In England it is beautiful as families go to a match. People have the right attitude."
Meanwhile Mancini expects Emmanuel Adebayor to return to the club on Sunday.
He has been on leave in Togo following the machine-gun attack on the national team coach before the African Nations Cup that left three people dead.