Now he is asking them to do the same at Wembley on Saturday.
And striker Jordan Bowery has spoken for the first time of the assault on him at Northampton Town last week.
“The biggest thing on Saturday is for fans to stay off the pitch,” said Clough.
“We asked our supporters to do it and they have respected that in the last few games. We are very, very proud of that.
“When you see some of the scenes that have happened in the last couple of weeks, our supporters have not set foot on the pitch and we ask them to keep doing that as we are very proud of that.”
Several incidents brought shame on the sport last week at big games with Sheffield United's Billy Sharp floored by a head butt from a Forest fan, who was jailed, only 24 hours before Bowery was barged into as three Northampton fans ran on the field throwing flares.
Bowery admitted it came as a shock but he knew he simply could not afford to react.
“I didn't know he was coming to me to be honest. He was looking right past me, so I wasn't expecting it,” he said.
“I thought he was going to just run right past but he ended up barging me and saying how the ref is a so-and-so. I was thinking why are you attacking me?
“If someone did that to you in the street the natural reaction is you wouldn't stand for it.
“But you know deep down there is a bigger picture.
“If someone reacted badly and did something to him you could miss the final and something could happen to him. It's just not worth it. You have just got to let the stewards take control.
“But it is getting out of hand at the minute, Things are happening everywhere and it needs to stop.
“You saw at Manchester City the crossbar getting snapped off. This all needs nipping in the bud to be honest.
“The more people are talking about it the more it seems to be happening. It is getting worse and I don't know what we can do about it.
“But it does need to be stopped as something worse could happen.
“The Billy Sharp one was terrible. What is stopping someone bringing a knife onto the pitch and attacking a player or a manager?
“Hopefully all the fans are responsible on Saturday and stay in their seats.”