Porro, who took aim at home fans after defeat to Chelsea, sought to apologise to the away support after the defeat at the City Ground.
He told Sky Sports: “The away fans do not deserve this.
“We can play on Tuesday and win in the Champions League, but in the Premier League it is different. Maybe more intensity, I do not know. But I feel especially sorry for the fans. The fans do not deserve this today.”
In response, former Forest manager O'Neill said on talkSPORT: “That’s a total ingratiation to the fans of himself to the fans that’s what that is.
“I’ll tell you something now, I can imagine these things existing sometimes when Brian Clough.
"And I have been hopeless in a game and he has just told me I’ve been hopeless in a match and then me going outside and going on social media and saying the fans deserve better than that.
“No, they deserve better from your performances (Porro) mate and you get a grip of yourself.
“I hope he's including himself in that group of players who didn't play so well...players, they’ll do your brain in!”