Something seemed to click for Manchester City at Bournemouth, jolting them into action and crystallising Pep Guardiola’s thinking. It may have been the end of March, but better late than never.

There are theories about exactly what happened on the south coast, when City battled back from a goal down – despite playing averagely – to book a spot in Sunday’s FA Cup semi-final. Guardiola has said he saw the spirit return. It was the day that Nico O’Reilly announced himself as a left back extraordinaire.

Those aspects are huge in City’s resurgence – five wins from six matches – but Guardiola’s tactical tweaks have also restored the vaunted control for which his City teams have always been renowned.

It is not deployed in every game but City tried a box midfield – four central midfielders in two lines – to crowd that section of the pitch and protect against transitions, an area where teams have dealt blow after blow since October. The tweaks have worked, with Aston Villa met by a mesh they could not get through on Tuesday night when attempting to blitz through City’s middle.

The full backs, Saturday’s hero O’Reilly and midweek match-winner Matheus Nunes went high and wide. The system does not work without those two performing, and some of Guardiola’s staff had worn puzzled expressions when the manager first suggested O’Reilly could do a job in that position.

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The strength of full backs Nico O’Reilly (left) and Matheus Nunes (right) cannot be understated

Jeremy Doku, explosive from a standing start, has been named on the team sheet just once since mid-March yet his impact against Villa, and Everton last weekend, suggests the Belgian has taken on the role of ‘finisher’.

He has played just 28 minutes in those two games but provided a stunning assist against Villa – storming past his marker and nudging the ball with the outside of the boot into a corridor of uncertainty – and opened up the game at Goodison to allow others to flourish.

‘Lately I’ve been open with the full backs,’ said Guardiola, who historically prefers such players to move infield rather than hug the white lines. ‘The moment Jeremy learns to play inside, because he has the quality to do it, he will play inside.

‘I’ve always played with the wingers high and wide, one against one. But lately, because for stability – more control and whatever – we play with full backs wide.’

At the moment, these cameos suit Doku. He has been criticised for a lack of end product but offers a difference, a thrust, that can ignite a crowd and his team-mates.

While City search for more of this control, Doku’s energy in the final quarter of games is hugely important.

His final ball is being worked on constantly. ‘He has improved a lot and will improve more,’ Guardiola added. ‘At the moment he makes the actions in one speed… when the moment you make the decision, you have to reduce the speed.

‘You have to be relaxed. You have to (look up). Otherwise you’re crossing just to cross, we’re not going to score a goal. But he is 22, he’s so young. He has something unique in terms of his speed.’

In the game against Brighton – the last before Guardiola’s tactical tweak – the average position of City’s full backs was inside their own half. They were also narrower than the full backs who played against Villa, who pushed much further up the pitch to offer width in attack.

Nunes netted the latest of winners to allow Man City to clinch their vital win against Aston Villa

Jeremy Doku may no longer be named to the first XI but he has taken up a key role as ‘finisher’

Bringing on the lad with a trick and loads of pace cannot be described as particularly revolutionary, but Guardiola has not done badly plugging the gaping defensive holes through which opponents have been flooding.

To do so with two full backs who do not fully understand the role is shrewd coaching but then we should not be surprised by that.

Nunes crossing for O’Reilly to score at Everton underlined the importance of their roles. O’Reilly then provided three wicked balls into the box that were not converted in midweek. There have been issues defensively, mostly from Nunes, but Ruben Dias and Josko Gvardiol have been sweeping up nicely.

Guardiola has altered formations in the past, although almost always as variants of a 4-3-3. This has been somewhat different, City playing with split strikers, James McAtee and Omar Marmoush, in wins over Villa and Crystal Palace and their new box formation.

A 4-1-4-1 system at Everton deviated from the idea, yet Bernardo Silva nominally operated on the right so the midfield was narrowed anyway.

This is all likely to be temporary. As Guardiola said, he wants natural wingers – inverted or otherwise – and there seemed to be a move towards the old Sterling-Sane era with Doku and Savinho being the preferred two.

Principles do not change so dramatically on a permanent basis, and this feels like a measure to just nudge City over the line in qualifying for the Champions League ahead of a busy summer transfer window that should push them into a new era.