Heading into the final stretch of the summer transfer window, the general sentiment surrounding Liverpool could be summed up in a few quotes:

• “Yes, he’s a necessity.”

• “Liverpool need leaders in defense and he’d be one of them.”

• “His valuation just gone up another €15 million!”

Those are former pros and current pundits Steven Gerrard, Jamie Redknapp, and Alan Shearer, respectively, speaking to the club’s need to sign Southampton center back Virgil Van Dijk. Yet the transfer window has slammed shut, Van Dijk remains in Southampton colors, and Liverpool’s defense is in tatters after losing 5-0 to Manchester City over the weekend.

Although the result was aided by an early red card to Sadio Mané, such a shocking scoreline will only intensify the calls for Jürgen Klopp to improve his defensive talent. But while the club could certainly upgrade the likes of Ragnar Klavan and Dejan Lovren, the core issue isn’t the players; it’s how they’re being asked to play.

Liverpool’s biggest defensive weakness? It’s Klopp.

Jürgen Klopp is one of the best managers in Europe because of his ability to construct a team that creates a lot of chances whether or not they control the ball. Only 10 teams this decade have taken more shots on target in a season than Liverpool did last season.

Through his own unique brand of aggressive pressing and counterpressing or the use of overlapping fullbacks in conjunction with wide attackers Philippe Coutinho and Mané, Klopp has pushed Liverpool back toward the top of the Premier League. The stats before this year began made it clear:

36-month trendline on Liverpool. Peak for Klopp so far was the December 27 game at Stoke. #statsbomblabs pic.twitter.com/18BKJfg3G7 — StatsBombIQ (@StatsBombIQ) July 29, 2017

Up until Saturday, their attack had remained red hot. Although Coutinho is yet to play a minute after the summerlong “will he or won’t he” saga concerning his potential move to Barcelona, Liverpool’s attacking trio of Mohamed Salah, Roberto Firmino, and Mané had no trouble making fools of Arsenal just before the international break.

The two main formations we’ve seen and will see going forward under Klopp are a 4–3–3 and 4–4–2 that uses four midfielders in a diamond shape. Each formation puts Liverpool in a state of attacking—whether or not they’re in possession. The 4–3–3 is more commonly used with Coutinho in mind—creating space for the Brazilian as an inside forward on the left wing by overloading his side with an overlapping fullback and other central midfielders. That allows him space to shoot, distribute, or link up with his teammates in dangerous areas.

Without Coutinho, Mané has slid over to the left, with Salah slotting in on the right, and the 25-year-old Senegalese international had been close to unstoppable. That is, until he nearly decapitated City’s goalkeeper, Ederson, in the 37th minute.

Few defenders in the world could’ve stopped the concession of chances and goals before or after the red card. At full strength, Klopp’s side did well to expose the space behind one of City’s most dangerous attacking options, Benjamin Mendy, but their overextension of players in possession and a lack of defensive movement in the midfield allowed their defenders to be attacked so directly in the first place.

Notice the positioning of the fullbacks in this clip. Although Liverpool regained possession, Alberto Moreno and Trent Alexander-Arnold are so high up the field. If they lose the ball, the center backs are stranded.

Here, all City ever had to do was break the first line of pressure, and they were in on Liverpool’s defense.

Liverpool’s fully leveraged attacking style—both fullbacks pushed high up the field, at least two of the three midfielders cycling into the box—is what makes the defense so vulnerable. Without a more balanced possession structure, only a handful of defenders can effectively do the job Klopp asks of his center backs, but they’re all already playing for better teams than Liverpool.

One of the staples of Klopp’s philosophy is his unique style of pressing. In essence, it’s a way of attacking without the ball. In Klopp’s own words: “If you win the ball back high up the pitch and you are close to the goal, it is only one pass away from a really good opportunity most of the time. … No playmaker in the world can be as good as a good counterpressing situation.”

Although the tactic’s effectiveness in the modern game is making it more of a necessity than an option, there’s an obvious risk a team takes when pressing as opposed to dropping into a defensive shell. The oversimplified videos you can see on Twitter or YouTube of old Dutch teams sending seven or eight players to press one opponent may be comical, but they’re perfect examples of what happens on a microscopic scale in today’s game. Pressing has always been an inherently risky idea.

A thing of beauty is a joy forever. Dutch relentless collective pressing at the 1974 World Cup pic.twitter.com/mOholxX6lm — Mohamed Moallim (@iammoallim) December 9, 2016

Liverpool creates a ton of high-quality chances because of the press, but it still doesn’t make the defenders’ jobs any easier. The same issue that plagues their possession play arises when their expansive press is beaten. With a high defensive line and a diffuse formation, a direct ball over the top can often completely expose the central defenders since it forces them to cover too much space.

Regardless of how risky the idea of pressing may be, it’s one married to the aspirations of the modern version of Liverpool Football Club. The move to bring in Klopp as manager during the 2015-16 season was more than just a power grab for a trendy manager; it was a statement of the team’s goals. The club had stopped consistently qualifying for the Champions League, and though they don’t have the same resources as domestic rivals like the Manchester clubs or Chelsea, they still wanted to compete with those clubs. “We used to think before then that if the other players are better, you have to lose,” Klopp said back in 2013 when he was still managing Borussia Dortmund, where he won two Bundesliga titles and made one Champions League final. “After that we learned anything is possible—you can beat better teams by using tactics.”

That certainly was the case last year, when Liverpool went undefeated (5-0-5) in 10 games against the other top six sides. But the pressing didn’t quite work against the teams that were willing to sit back and counter, as Klopp’s side struggled for consistency (17-5-6) against the rest of the league.

Since teams who are willing to sit in against the Reds allow space up to a certain point, Liverpool’s possession against these sides often progresses forward without much danger. Klopp’s men can comfortably move the ball past their own halfway line before engaging meaningful defensive pressure, so the entire formation moves forward in order to attempt to break down the opposition. High and wide positioning of fullbacks is the easiest way to stretch and create space against compact defenses, but that leaves Liverpool open to the threat of a counterattack. If an opponent can win the ball and get forward after Liverpool has pinned them into their defensive third, they’ll often just have to beat a pair of center backs to create a chance on goal.

For all the qualities someone like Van Dijk possesses—pace, strength, aerial ability, and an impressive composure on the ball—the addition of the Dutchman would do little to quell Liverpool’s concession of chances. He might help them handle a few more counterattacks per season, but in the end he’ll likely end up taking the same abuse that Lovren or Klavan are subjected to week in and week out.

Lovren came over from the same club as Van Dijk, and he looked like a top-level defender at Southampton, but the Saints use a far less aggressive defensive pressing style than Liverpool—one that’s mainly focused on moving the opposition into the least dangerous areas of the pitch—so it creates layers of safety for its defenders.

A more direct solution would be for Klopp to tweak his system. The club could focus more on build-up play. Rather than consistently forcing the ball forward as Liverpool do, they could cycle the ball around the defense and the midfield to draw the defense out of its shell. That would both create space behind for Liverpool to attack into, and it would leave them less vulnerable to the counter.

Klopp can also do a better job in organizing the compactness of his formation when pressing. Part of his job is ensuring Liverpool don’t fall prey to an Alexis Sánchez situation, wherein a player ruins the defensive shape by running around like a headless chicken. After the club’s 3-1 over Arsenal in March, he bemoaned the team’s lack of cohesion: “The problem is when we’re not compact and Adam [Lallana] does the same [as Sánchez]. Then he opens the gap for an opponent and we have a 1v1 in a big area.”

Another area where Klopp could improve as a manager is in his game-by-game management. José Mourinho’s coaching philosophy centers on forcing your opponent to play how you want them to. Klopp’s team tends to play the same way—no matter the opponent. That’s why they’ll struggle against a side that sits deep and then come back the next week and batter a member of the top six. While their most recent loss to Manchester City may seem out of character, Pep Guardiola actually dialed down his team’s attacking aggression. City, instead, asked the question of Liverpool’s ability to break them down by employing a more defensive approach, and despite a handful of semi-dangerous attacks, Klopp’s team were second best even before the red card.

City were doing well enough before Mane kicked Ederson in the face, but afterward it was just silly. pic.twitter.com/Do5b83Wsj1 — Caley Graphics (@Caley_graphics) September 9, 2017

If Liverpool are to be consistent in their qualification for the Champions League, much less challenge for the title, they’ll need to progress in more sustainable ways under their fiery manager as opposed to spending on an expensive centerback. Just take their four games this season: A 3-3 draw against Watford, a 1-0 win over Crystal Palace, and a 4-0 win over Arsenal, and a 5-0 loss to City. That’s as up-and-down as it gets. Overall, 1.75 points per game isn’t a bad return when half the games were against top-six sides, but it’s just as predictable when Liverpool are forced to play a certain way as last year. Now, more than any other defender or midfielder, Liverpool need Jürgen Klopp to evolve.