With Ola Aina injured and Alex Moreno ineligible, Nuno Espirito Santo must find a new solution against Unai Emery’s Aston Villa on Saturday. But variations in tactics and personnel have been a key feature of Nottingham Forest’s success this season.

In seeking to explain Forest’s extraordinary form, a run that has taken them to third in the Premier League table and has supporters dreaming of the Champions League, not to mention FA Cup glory, it is the continuity under Nuno that has often been cited.

There is truth to that. No team in the Premier League has used so few different players this season, just 23. In total, Forest have made 49 changes to their starting line-up. Again, that is low. Only three teams in the competition have made fewer.

But those numbers mask the moments when Nuno does intervene, switching players’ positions or shifting formations. Morgan Gibbs-White can move deeper. Elliot Anderson and Nico Dominguez can go wide. Anthony Elanga operates all across the forward line.

Most obviously, there is the use of Morato, the 23-year-old defender signed from Benfica in the summer. He has started only four Premier League games but been introduced off the bench on 17 occasions, his arrival often signalling a change in Forest’s formation.

That was the case in the 1-0 win over Manchester United on Tuesday. Already ahead after Elanga’s early goal, the injury to Aina was the catalyst not just for a like-for-like switch but for Nuno to go to a back three. That adaptability has become a strength.

“What we have got is the understanding of why,” Nuno tells Sky Sports. “Everybody knew the reason behind the change. It was not only the injury – we changed two players, changed the shape and you only can do that if the players understand your message.

“Because you do not have time to tell them, ‘we are going to do this, this and this’. It is something that we have done before and we are ready to do it and apply it during the game.

“That is a big process in terms of progress, in terms of understanding the game by ourselves so the players know what we are doing and they adapt accordingly.

“We only can do that because we did it before. We worked on it for many hours on the training ground and we put it to test during the competition. It would be absurd for us to make a decision, doing something that we have never done before.”

It is a product of the work Forest did in the summer. “In pre-season, I think almost all of the games we started with a back three. It was not our main shape, but that was the moment to test it because we need to see the mistakes so we can correct them.”

He talks of Morato “giving us a lot of good things” and he believes this ability to change defensive shape has won Forest points. “Since the beginning of the season, it was a shape that we used many times during games, especially to close games down.”

That ability to move seamlessly between systems is a testament to his players, but also to their coach and the trust that he has earned. Forest were winning against United. If they did not believe in his work, they might have wondered why a change was needed.

“If you ask me, the reason behind it against United, it was not the result,” Nuno explains. “We were not in control of the game. We were not dominant without the ball. We had fragility, we had problems. United were creating problems with the ball.”

The aim of the change, then? “Solving that first and trying then to stay in the game and progress. I think at half-time, we adjusted better and we played a good second half.”

It is that one line – ‘dominant without the ball’ – that reveals plenty about how Nuno sees the game. For some of his Premier League peers, that might be regarded as a contradiction in terms, such is the obsession with possession in modern football.

But Nuno, the newly-crowned manager of the month for March – surely the manager of the season if Forest finish in the top five, let alone third – is achieving all this with the Premier League’s lowest possession numbers. This is where he warms to his theme.

“You do not have to have the ball to have control. It is absurd to think that you control the game because you control the ball.”

He adds: “Control or dominance of the game is, if you want in a very personal view, when the game is going the way you think it is going. You predict something that is going to happen and see if things are happening the way you think that you are expecting.

“You are in control, you are in dominance, even though you do not have the ball. But when you do not have control of anything and you do not realise what is going on, you have lost control of the game.” And for Nuno, that is the moment when he needs to act.

“I think it is important to recognise that and then adjust according to it. Basically, when something works well, why do you have to change? That is the basic principle of life. But when it comes to problems, there comes the need to interfere, create a new solution.”

Nuno can be a little reluctant to talk tactics. There are those coaches willing to offer chapter and verse about the details but, on the record at least, the Portuguese guards his ideas closely. At one point, he stops himself. “I am giving you too much,” he says.

Perhaps this unwillingness to sell his idea to the media can lead to unfair criticism. As recently as last weekend, Wayne Rooney was describing Nuno’s team selection for the FA Cup quarter-final against Brighton as “beyond belief”, but Forest still won the game.

Nuno is unconcerned. He has his methods and they are doing the talking for him. And besides, those who matter most are all in. “The more crucial aspect, I think, is the players,” he says at one point in the conversation. Players who continue to improve.

He mentions not just Elanga but Callum Hudson-Odoi, Jota Silva and Ramon Sosa being able to play anywhere across the front line. He speaks about the midfielders behind them who “can play wide, higher in the pockets” and the possibilities this brings.

Always, it is about how these players interact. Chris Wood moving towards the ball and Elanga running beyond the defence, for example. “Not one piece by himself, but how two or three pieces get together.” And such is the buy-in now, they are all ready to work.

“That was one of the things we needed to improve. Our off-ball work is much better now. It requires knowledge of the game, the spaces to occupy, the lines that you want to cut, how to create the right moment for the other team-mates to press. It is hard work.

“I think nowadays everybody, as a professional player, realises that the game is not only with the ball. So we do not have to be worried about players not competing when we do not have the ball. It is the joy of having the ball versus the joy of competing well.”

Forest are certainly competing now. They have surprised everyone this season. Even Nuno? “Yes, of course. I think the initial expectations regarding us as a club were not these. Just look at the previous seasons, even last season, the problems that we had.”

From one place above the relegation zone at the end of last season to two places off top as this one reaches its climax, Forest continue to confound. Thanks to their tweaks, it seems their Premier League opponents still have not found a way to stop them.

“Do they figure it out? I don’t know,” says Nuno. “Ask them.”

Watch Aston Villa vs Nottingham Forest live on Saturday Night Football from 5pm on Sky Sports Premier League; kick-off 5.30pm. Stream with NOW.

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