However, O'Neill was not buying into the Italians excuses whilst suggesting it was his team's best performance of the season to make it three wins in a row at home against City.
"Honestly, I am really not particularly bothered, I am genuinely not bothered about what Roberto Mancini would say about the team," he said.
"I have seen it before with other managers. I'm not bothered. I thought we were terrific today.
"Considering the opposition, I would have to say yes (it was our best performance).
"We gained a bit of confidence form winning against Southampton and took that into the game, but we knew there would be times when we would have to play without the ball and we would have to defend strongly, and we did both of those very well.
"And yet we were able to carve out some great chances in the game."