The Blues have made an encouraging start to life back in the Premier League, beating Sunderland, Crystal Palace and Fulham courtesy of late goals and looking competitive for large periods in defeats to Manchester United, Liverpool, Everton and Manchester City.

It means belief will be high heading into a Friday night home clash against a Forest side that have just five points and five goals to their name thus far. O'Neil, however, wants to make sure that players and fans don't get ahead of themselves.

"They're going to try and make it a really frustrating night for us - everything we do is going to be tested again," said the Blues boss.

"We can't just live off the fact that we've done okay for the last seven games. That's not going to help us one bit.

"It was a decent effort against a good Manchester City side, obviously, but we need to literally start again from zero. We need to step on the pitch and understand we haven't done a thing. This starts again now for 95 minutes. And we need to be at our very, very best.

"We just keep resetting the group to get ready to go to battle every six, seven days. It's not like we've made a statement and we're going to be fine against everybody. I think there's an awful lot of work to do still here this season. 

"Seven games in, nine points, but still a lot of work ahead of us. No one's getting carried away."

Nottingham Forest have had a slow start to the season under new boss Oliver Glasner and sit 19th in the Premier League table. Three of their losses have been a by a 1-0 scoreline though, with the East Midlands side giving Arsenal a run for the money last weekend.

"This is a very different test coming against Nottingham Forest, but equally difficult," insisted O'Neil. "I've watched all of their games and they've performed far better than their points tally would suggest.

"If they were boxing matches you definitely wouldn't have them as the loser in them. They always seem to be the ones that are creating chances, so this is a real big test for us.

"[With Glasner there] It's just like watching Crystal Palace, really. They're literally exactly the same. And it was always a very, very, very difficult game against his Palace sides. You see the success he had there.

"Obviously, he hasn't been with the group as long, so they won't know it as well as the group that he left. But it's just an incredibly difficult style to play against.

"It is really a pretty opposite end of the spectrum, game-wise, for us following on from Man City. There we prepare to to defend low, keep bodies in the way and try to be the transition team. Now we face a very, very direct team who play forward almost instantly when they regain the ball.

"You only have to watch Oliver on the sidelines. As soon as they win the ball back, his pointy finger comes up and he points straight to the top of the pitch! Literally every clip I've watched, so it's obviously something that they work hard on.

"They're very low risk. They don't make loads of short, intricate passes. They defend pretty low with a back five, but can jump really aggressively and transition really well. As soon as they win the ball back, they try and transition to the goal really, really quickly and it can be difficult to stop.

"Even against Arsenal, Tottenham, Liverpool, they still found a way to look like a very threatening side without much of the ball."

"It's been an interesting watch for me this week, trying to get some ideas on how we best go about stopping them."

He added: "It's Friday night at Portman Road. under the lights and another opportunity to put more points on the table.

"The boys are excited. This is a game that is going to take a real good performance from us."