Liverpool striker Suarez is currently serving an eight-game ban after being found guilty of racially abusing Manchester United defender Evra and will not face City in their Carling Cup semi-final first leg on Wednesday night.
The Uruguay striker claimed the term with which he was found to have insulted Evra is not derogatory in his native country, but last week did issue a broad apology for any offence caused.
Mancini said: "I think that sometimes a situation like this can happen on the pitch. It is important to apologise for what he did.
"Sometimes on the pitch you can do something that you don't want to do. You are nervous. You don't think on the pitch. I don't think Suarez is a racist. He made a mistake? Probably, yes.
"Everyone can do a mistake sometimes. It is impossible that we are always perfect. It is important to say, 'I am sorry, I made a mistake, I apologise for this and I accept the charge'."
Liverpool have been heavily criticised for their strong backing of Suarez and their handling of the whole affair, which included players wearing T-shirts in support of Suarez while warming up before the Barclays Premier League fixture at Wigan.
Mancini, speaking at a press conference to preview Wednesday's game at the Etihad Stadium, said he thought that was "maybe a mistake".
A former striker with Sampdoria, Lazio and Italy, Mancini is well aware of how comments can be made in the heat of the moment on the field.
When asked what was ever said to him as a player, the 47-year-old said: "Everything. In 20 years? I understand. I didn't cry for this.
"I repeat, on the pitch, anything can happen because you don't think, because you are tired, because you are stupid when you are young. I said some things but not important things like a racist word."
