Is the signing of Wayne Rooney driven by reasons of football or reasons of sentimentality? Perhaps it doesn't matter. Never before in the Premier League era have their fans looked forward to a season this much.

If only the same could be said on the other side of Stanley Park.

On the Liverpool Echo's website, rolling news coverage began on Tuesday morning with a GIF of Smithers from "The Simpsons" pacing up and down nervously, which seemed as appropriate an approximation of the mood as any. Last season ended well, with back-to-back wins over West Ham and Middlesbrough securing Champions League football, but there was more than enough in the home defeat to Crystal Palace at the end of April to suggest that Jurgen Klopp had plenty of room for improvement in the summer.

The arrival of Mo Salah, for a record fee of £39 million, will lessen the reliance on Sadio Mane, profoundly missed when he left for international duty, and the capture of Dominic Solanke (who is expected to start in the development squad) could prove to be a real bargain. But it's at the back where the real problems lie.

Last season was the seventh successive Premier League campaign in which Liverpool have conceded more goals than they played games. The parsimonious days of Rafa Benitez, whose teams conceded an average of 26.75 goals per season in the four seasons between 2005-06 and 2008-09, are long gone. Klopp's Liverpool (who shipped 42) were certainly fun to watch. With 78 goals, they scored more than any Liverpool team in the Premier League era -- apart from Brendan Rodgers' 101-goal side in 2013-14.

It was a haul as big as that accrued by the last Liverpool title-winning team of 1989-90, but they were frequently compromised by horrible moments of defensive weakness, particularly at set-pieces. Reinforcements were expected, but with preseason already underway, they haven't arrived yet.

We can assume that Klopp has no plans to buy a new goalkeeper. Simon Mignolet's performances improved markedly after the arrival of Loris Karius, who proved quite the motivator, and Danny Ward, a hero of Huddersfield's promotion campaign, will not be allowed to leave on loan. From that three-way tussle, a trusted No. 1 will emerge. But if the improvement isn't going to be between the sticks, you'd expect it to at least be in front of them.

Andrew Powell/Liverpool FC via Getty Images

Joel Matip enjoyed a promising debut season at Anfield and Dejan Lovren has been steadily improving, but there isn't much in the locker after that. In the "Which Rival Champions League Clubs Would Sign My Players?" test, Ragnar Klavan scores poorly and there seems to be little chance of Mamadou Sakho and Klopp making up. Liverpool need something more if they're to retain their top-four place, let alone push for the title.

They need something in the middle, too, but Red Bull Leipzig have no intention of letting preferred target Naby Keita go for anything less than an eye-watering fee that would almost double that paid for Salah. The Guinean midfielder looks an all-action, nuclear-powered creative phenomenon, but will the owners really sanction that sort of spending? It would be quite a change of policy.

By contrast, Everton have already signed six players, and it seems that they are just as ambitious off the pitch, too. Leaked documents appeared on social media this week that suggested the club's plans for a new stadium are far grander than first thought. It may yet come to nothing, but at 60,000 seats, the Bramley Moore Dock development would be larger than Anfield. You can imagine how well that has gone down in the blue parts of Merseyside.

With nearly two months of business still to be done, there really is no need to panic. But when has panic ever required legitimacy? Liverpool's supporters can see Manchester United spending £75m on one player; they can see Arsenal spending £53m on one player; they can see Manchester City spending £43m on one player; they can even see Chelsea spending £31m on a central defender. But far worse than that, they can see their next-door neighbours flexing their muscles and growing more powerful with every signing.

The mood in the blue bits of Merseyside is buoyant. For the reds, there are only increasing concerns.