Arne Slot faces a significant challenge in revitalizing Liverpool, and while unlocking the potential of record signing Alexander Isak and getting Mohamed Salah back to his prolific best are pressing concerns, the team's defensive frailties appear to be a more immediate and profound issue. The recent 2-1 defeat against Manchester United at Anfield, their first in over nine years, highlighted the Reds' crumbling foundations at the back. This loss marked Liverpool's fourth consecutive defeat, a worrying trend for the reigning Premier League champions.

Slot openly acknowledged the challenge ahead after the loss to United, attributing the defeat to wasteful finishing and recurring lapses in defending set-pieces. Harry Maguire's late header sealed the victory for United, further exposing Liverpool's vulnerability in defending crosses and set plays. Despite creating numerous clear-cut chances, Liverpool were unable to capitalize, with Cody Gakpo hitting the woodwork three times and missing a crucial late opportunity. Slot lamented that his team should not have lost the game given the chances they created.

The struggles of Isak and Salah have undoubtedly contributed to Liverpool's recent woes. Isak, the £125 million striker, has been largely anonymous in the No. 9 role, struggling to find the net and make a significant impact. Salah, despite his stellar record against Manchester United, has also been below par, failing to replicate his usual goal-scoring exploits.

However, the defensive issues seem to run deeper than individual struggles in attack. Liverpool have conceded a series of preventable goals in recent matches, displaying a lack of organization and communication at the back. Virgil van Dijk, usually a rock in the heart of the defense, expressed his frustration after the United defeat, lamenting a "very sloppy goal" and urging the team to "stay humble and improve ASAP".

The numbers paint a concerning picture of Liverpool's defensive decline. They have conceded late goals in multiple games, and their inability to defend set-pieces has become a recurring theme. The usually reliable partnership between Salah and Trent Alexander-Arnold has also been disrupted, impacting the team's overall cohesion.

Slot has experimented with different defensive lineups, but is yet to find a stable and effective combination. The summer changes and the search for his best XI have undoubtedly contributed to the team's inconsistency. The absence of a solid defensive foundation has made it difficult for Liverpool to control games and maintain leads.

While Slot needs to find a way to get Isak firing and reignite Salah's spark, addressing the defensive vulnerabilities is paramount. A tighter defense will not only prevent the opposition from scoring but also provide a platform for the attack to flourish. Slot's immediate focus must be on solidifying the backline, improving communication and organization, and finding a consistent defensive unit. Only then can Liverpool hope to overcome their recent slump and mount a serious title challenge.