From their makeshift centre-back pairing to Arsene Wenger's tactical shortcomings, Gunners fans at the Emirates Stadium on Sunday had seen it all before Brand new season, same old problems for Arsenal. When Granit Xhaka was signed for £35 million at the start of the summer transfer window, Gunners fans were rightly excited by what was expected to follow. Instead, Arsene Wenger’s side came into their opening game of the season relying on an inexperienced, unproven centre-back pairing they had never fielded in the Premier League before.

While transfers will be the main talking point in the aftermath of Arsenal’s dismal defeat to Liverpool, Jurgen Klopp's tactical victory over the league’s longest-serving manager should not be overlooked. Klopp and his assistant Zeljko Buvac spent much of the match pacing up and down the technical area, screaming instructions at their players and encouraging them to challenge Arsenal’s young defenders.

Shkodran Mustafi is expected to sign for the Gunners in the coming days as a reaction to the injuries suffered by Per Mertesacker and Gabriel, but the 24-year-old's arrival might not be enough. Several first-team players, including Mesut Ozil, Olivier Giroud and Laurent Koscielny, were absent for the visit of Klopp’s men and that is the excuse Wenger will undoubtedly look to when he is asked to explain the defeat.

Arsenal once again showed character and spirit to bring the score back to 4-3 with 13 minutes to go, but it was typical of them in that the improvement only arrived after they had made life much harder for themselves than they needed to.

Liverpool are the first team to score four goals at the Emirates Stadium since Chelsea in 2009 and Philippe Coutinho orchestrated most of the scintillating football Klopp’s men played, scoring two goals. The 19 passes leading up to his second goal plus Sadio Mane’s unchallenged run into the Arsenal box for Liverpool's fourth were lessons in sharp, purposeful football. Both teams came into the game off the back of impressive pre-season results, but Liverpool's 4-0 thrashing of Barcelona now looks much more significant than Arsenal's victory over Manchester City.

Chants of "spend some f****** money" directed at Wenger by a large section of the home supporters are nothing new. Arsenal's failure to buy an outfield player in last summer's transfer window arguably cost them the Premier League title and it must be put right in what remains of the current transfer window if they are to compete with their improved domestic rivals.

This season's title race is set to be more competitive than ever, with at least six teams in with a legitimate chance, and unless Wenger invests in at least two top-class players in the coming weeks the Gunners will be left behind.

Beyond the transfer problem, several other questions will be asked by Arsenal fans after this match. Why did Theo Walcott step up to take the penalty when the likes of Alexis Sanchez and Aaron Ramsey were on the pitch? How is Joel Campbell not even deserving of a place on the bench despite having such a fantastic pre-season? Was it the correct decision to start 20-year-old Rob Holding, a youngster who has never played a Premier League game, when Nacho Monreal is able to fill in at centre-back?

There are a few positives for Wenger to take, of course; Walcott's goal may be the tonic he needed to kick-start his season and return to scoring form, while the introduction of Alex Oxlade-Chamberlain in the second half showed exactly why he should be given a place in the starting XI. They will be overshadowed, though, by a full-time score which many fans will see as another damning indictment of the club's current regime.

Not for the first time, boos were heard at the final whistle. It was an almost predictable performance from an Arsenal side who should have been ambitious enough to have already secured the reinforcements needed to mount a genuine challenge to win the Premier League this season.

Wenger still has time to buy, and the hope will be that this result is enough of a wake-up call to spur him into action. For now, Arsenal have returned with the same old problems.