Before Paris Saint-Germain’s Champions League semi-final second leg away to Bayern Munich, manager Luis Enrique insisted they would play as they did in the home leg.

But while last week’s match in Paris was a thrilling 5-4 victory for his side, the return in Munich on Wednesday was a more sedate 1-1 draw. PSG did play with similar principles, and were probably the better side, but they were also more cautious than they’d been in at the Parc des Princes, and that was partly because the line-up was different.

Injury meant they were without right-back Achraf Hakimi, the player who epitomised his side’s energetic, aggressive nature without possession in that first leg by constantly sprinting 50 yards up the pitch to close down Bayern’s left-back.

His replacement on the right of PSG’s defence was Warren Zaire-Emery, a midfielder who deputised in that role for much of the winter. That meant someone else had to play in the centre, and therefore a recall for Fabian Ruiz, whose season has been compromised by injury and wasn’t fully fit.

Ruiz played a very different role last night to Zaire-Emery’s in the first leg, and that changed PSG. Zaire-Emery was all about forward running in Paris, trying to exploit gaps in the Bayern defence. In the return, Ruiz, the 30-year-old Spain international, was more concerned with finding gaps down the left flank.

Here, seven minutes in, is a good example of the positions he took up, and it’s significant that Bayern manager Vincent Kompany seems to be gesturing to his players to close him down.

By this point, though, the damage is done.

For all the goals in the first leg, the return was really decided by a single goal, scored two minutes in. And it was all about Ruiz’s positioning.

As PSG play out from the back, Ruiz — a central midfielder on paper but wide on the left here — checks over his shoulder to make sure he’s not being marked. As the move develops, he moves out nearer to the touchline, into a pocket of space where Bayern aren’t sure how to close him down.

Meanwhile, Khvicha Kvaratskhelia drops into space between the lines, dragging centre-back Dayot Upamecano up the pitch, before receiving a pass and prodding it out to Ruiz. His first-time return ball beats Upamecano and right-back Konrad Laimer, and Kvaratskhelia is free to run through and pull it back for Ousmane Dembele to hammer a shot home.

Ruiz continued to do this throughout the first half, making runs from a left-centre midfield position to the left flank, seemingly untracked by Bayern.

Here, that allowed him to be the link man between Kvaratskhelia, the left-winger, and Desire Doue, who drifts from a centre-forward position to the visitors’ left flank and drags Upamecano out wide. Essentially, this is PSG playing the same pass twice, to progress the ball up that wing.

On other occasions, Ruiz was happy dropping in at left-back as PSG built from that side of the pitch.

Here, this allows left-back Nuno Mendes to effectively take up the position Ruiz had been in for much of the first half, knocking a pass inside and allowing Doue and Kvaratskhelia to get on the ball again.

The map of Ruiz’s passes underlines the extent to which he played on the left in Munich rather than as a central midfielder:

Amid the dribbling qualities of PSG’s attackers, the technical quality of Portugal international midfielders Vitinha and Joao Neves alongside him in the engine room, the speed of their full-backs and the solid centre-backs, Ruiz’s importance is underestimated.

It shouldn’t be forgotten that he was truly outstanding for Spain when they won the European Championship two years ago, and probably unfortunate that his midfield colleague Rodri was voted player of the tournament.

He’s so difficult to pin down, as a midfielder comfortable dropping into defence and playing out under pressure, adept at making late runs into the box to provide a goalscoring threat, and happy drawing wide to use his favoured left foot to play passes down the line.

Assuming Hakimi is fit enough to start the May 30 final against Arsenal at right-back, head coach Luis Enrique will have a tough decision to make between Zaire-Emery and Ruiz for the third midfield spot.

Zaire-Emery has played more minutes for PSG than anyone else this season, but Ruiz is so often pivotal in football’s biggest matches.