Reasons to be fearful: Causes for concern at Anfield

Benitez was approached in January (GETTY IMAGES)

1. Are Liverpool flat-track bullies?

In defeating Stoke, Bolton, Burnley, West Ham and Hull for their five Premier League victories this season, Liverpool have run in a total of 20 goals at an impressive average of four per game.

Yet that is not exactly a roll-call of English football's big-hitters; not one of them is currently in the top half of the table. Faced by their only two opponents who are, and were last season, Rafael Benitez's side lost to both Tottenham and Aston Villa, going down 2-1 at White Hart Lane on the opening weekend of the season, then losing 3-1 to Villa at Anfield.

In the Champions League they managed a laboured 1-0 win over Debrecen of Hungary, who have just been thrashed 4-0 at home by Lyons.

2. Should Xabi Alonso have been allowed to leave?

If Benitez fails to land a major trophy this season, the departure of the cultured Spanish midfielder will go down as a key reason.

The manager claims his hand was forced, in part by the player's agent. But Alonso was under contract and his disenchantment at Anfield stemmed from Benitez's willingness to sell him to Juventus during the previous summer in an attempt to bring in Gareth Barry.

Liverpool have ended up with the worst of both worlds: no Barry and no Alonso. Benitez retains more faith than most in Lucas Leiva, but when Javier Mascherano is absent, as on Tuesday, there is scant protection in front of the defence.

3. Does the squad possess adequate back-up?

With Alonso gone, and Alberto Aquilani still not fit, an injury to Mascherano highlights a threadbare quality to the defensive section of the midfield: Lucas and fellow Brazilian Fabio Aurelio could not cope in Florence. Dropping Steven Gerrard back there pulls him out of his best position just behind Fernando Torres, as even the mercurial captain cannot be in two places at once.

In trouble on Tuesday night, Benitez turned to Andrei Voronin and Ryan Babel, for the want of anything better, replacing Emiliano Insua and Dirk Kuyt respectively. The most worrying prospect for the Liverpool manager remains a serious injury to Gerrard or Torres.

4. Is Jamie Carragher past his best?

The passionate Scouse centre-back is admirably self-critical, a trait Benitez encourages by privately highlighting every player's mistakes. Carragher cannot be pleased with recent performances in the more difficult games, especially those against West Ham, where he was given a hard time by the young but pacy Zavon Hines, and Fiorentina. Worryingly, his uncertainty appears to be affecting Martin Skrtel, with whom he has not formed as solid a partnership as he enjoyed for years with the now-departed Sami Hyypia.

Will the manager be tempted to try Skrtel with either Daniel Agger, who made a successful comeback in the reserves on Tuesday, or Sotirios Kyrgiakos?

5. How to approach the Chelsea game on Sunday?

For the first time this season, Liverpool face one of the other big four – or is it now five? – when they travel to Stamford Bridge. They cannot afford another defeat; of their rivals, only Arsenal have also already lost two Premier League games, and both of those were away to the Manchester clubs.

So does Benitez adopt a bold approach as in the epic 4-4 Champions League quarter-final at Chelsea last season, trying to secure a morale-boosting victory or, as seems more likely, tighten up and hope as in previous visits to hit Chelsea on the break? After all, last season Liverpool mounted a strong rearguard action to win there 1-0 in the league.