Blackburn Rovers had to reshuffle the pack on Saturday with key players absent against Bristol City.

John Eustace was without first-choice full-backs Callum Brittain and Harry Pickering, whilst Andi Weimann was also not fit to start. Danny Batth and Lewis Baker came in for their full league debuts, with Hayden Carter switching to right-back.

That forced not just a change of personnel but a change of tactics for Eustace, who was forced to make alterations to Rovers' usual build-up patterns to accommodate for the absences.

However, it worked a treat, with Rovers barely missing a beat, stifling Bristol City and still posing a threat on the counter-attack.

In this tactical breakdown, we'll look at what changed, why it changed and what the effect was.

How do Blackburn Rovers normally set-up?

Eustace has exclusively used a 4-2-3-1 formation out of possession this season. Whilst he deviated to 5-4-1, at times, last year, he has stuck with the same shape throughout pre-season and in the Championship this term.

The first thing to explain is the shape that Blackburn Rovers use when they don't have the ball is a 4-2-3-1, known as out of possession structure. However, when teams have the ball, they often set-up differently and that is their in-possession structure.

When Rovers have the ball, they shift to a 3-4-2-1. Harry Pickering, the left-back, becomes a third centre-back in possession to help Rovers move possession through the pitch.

Callum Brittain, the right-back, pushes high and wide into a wing-back role to provide width. Ryan Hedges, the left-winger, does the same on the opposite flank.

That allows the right-winger, in the Oxford game this was Joe Rankin-Costello, to move centrally and become a second number 10 alongside Tyrhys Dolan. They can then both operate behind the central striker, Yuki Ohashi.

Blackburn Rovers' tactical set-up against Oxford in a 3-4-2-1. Callum Brittain is circled, with the back three in possession. Joe Rankin-Costello has moved central as a second number 10.Blackburn Rovers' tactical set-up against Oxford in a 3-4-2-1. Callum Brittain is circled, with the back three in possession. Joe Rankin-Costello has moved central as a second number 10. (Image: Blackburn Rovers)

When the ball is lost, Rovers revert to their standard 4-2-3-1 shape, with Pickering moving to left-back, Brittain dropping deeper to right-back and Rankin-Costello moving wide to defend the right channel.

This structure is very popular among head coaches as it gives great coverage across the pitch. Some, such as Manchester City, prefer to have a full-back inverting into the pitch, which Rankin-Costello did previously under Jon Dahl Tomasson when playing right-back. Under Eustace, Rovers ask the right-winger to invert and that helps to create an overload in the centre.

That shape suits the personnel Rovers have. Pickering is a very good passer from deep areas but isn't the most natural attacker. Brittain is the opposite, he is very good at crossing and attacking down the wing.

Rankin-Costello prefers to play in central positions whilst Hedges is comfortable playing as a natural winger, whether on the left or the right.

What changed against Bristol City?

In essence, Rovers flipped their build-up patterns. It was the same movements but this time on the opposite flank because of the injuries.

With Brittain absent, Carter was at right-back. Now he is more comfortable as a centre-back in build-up for obvious reasons. Whereas on the left, Beck is a more attacking full-back, akin to Brittain.

Equally, Lewis Baker is a central midfielder, asked to do a job on the left. So he was the player that was moving centrally, but from the left, to create the overload in the middle.

Blackburn Rovers' tactical set-up against Oxford in a 3-4-2-1. Callum Brittain is circled, with the back three in possession. Joe Rankin-Costello has moved central as a second number 10.Blackburn Rovers' tactical set-up against Oxford in a 3-4-2-1. Callum Brittain is circled, with the back three in possession. Joe Rankin-Costello has moved central as a second number 10. (Image: Blackburn Rovers)

So Rovers still had the same 3-4-2-1 shape when they had the ball, but it was mirrored from right to left to create the overload in the centre of the pitch. That accommodated the changes in personnel but without causing too much disruption.

What about without the ball?

When Blackburn Rovers were defending, it was the same 4-2-3-1 shape. The back four was the same and Baker was tasked with covering the left channel defensively, as Weimann or Rankin-Costello did from the right in previous games.

Blackburn Rovers' tactical set-up against Bristol City in a 4-2-3-1. Lewis Baker has moved to the left when they don't have the ball..Blackburn Rovers' tactical set-up against Bristol City in a 4-2-3-1. Lewis Baker has moved to the left when they don't have the ball. (Image: Blackburn Rovers)

To do this, you need intelligent players but credit to Eustace for finding solutions without having to tear up Rovers' patterns of play.