What has gone wrong in Liverpool's title defence?

The champions find themselves down in fourth with Klopp claiming just a return to the Champions League next season would be a success given his side's struggles of late.

However, an unpredictable season due to empty stadiums and a packed fixture schedule, has meant no side has stormed clear like the Reds did last season.

Liverpool are still just four points off the top, so can their problems be resolved in time to retain their title?

Injuries

The loss of the talismanic Virgil van Dijk for the season to knee ligament damage would have been a big enough loss on its own to challenge Liverpool's title credentials.

However, the Dutchman's absence has been compounded by another long-term injury to a centre-back in Joe Gomez and Joel Matip's fitness problems.

Without a recognised senior centre-back in recent weeks Klopp has resorted to fielding midfielders Fabinho and Jordan Henderson at the back.

Liverpool's defensive record since Van Dijk's injury is still impressive, conceding just eight goals in 13 games.

But that has come at the expense of destabilising the front-foot style that has restored the glory days at Anfield under Klopp.

Without the comfort of Van Dijk and Gomez's pace to hold a high line and the ball-winning ability of Fabinho and Henderson in midfield, Liverpool's pressing game has eased off.

Injuries have also taking their toll further forward without Diogo Jota over the past month.

The Portuguese made a blistering start to his Liverpool career, scoring seven times in his first nine appearances.

Since Jota suffered a costly knee injury in a Champions League dead rubber against Midtjylland in early December, Klopp is short on options to provide competition for Mohamed Salah, Sadio Mane and Roberto Firmino.

Father time against front three?

Salah, Mane and Firmino will live long in even Liverpool's storied history as a front three that ended the Reds' long wait for a league title and delivered a sixth European Cup.

Over the past four seasons they have been the perfect foil for one another, combining to score 248 goals.  

However, all three are at the least approaching the latter end of their peak years. Salah and Mane will be 29 this year, while Firmino turns 30 in October.

Jota's injury offered little chance for respite over the busy festive schedule and with all three failing to find their form, the goals have dried up.

For the first time since 2005, Liverpool have not scored in three consecutive league games.

Salah's complaints about not being made captain for the match against Midtjylland in a rare interview with Spanish newspaper AS was interpreted as the Egyptian inviting offers from Real Madrid.

Yet the time may have passed for Liverpool to cash in their major asset at the right time as they did in selling Philippe Coutinho to Barcelona three years ago.

Hunger gone?

Klopp's men followed up on an unprecedented title showdown with Manchester City in 2018/19, which saw them miss out despite amassing 97 points, with a club record 99 points last season.

After also reaching two Champions League finals in the past three seasons and the often soulless atmosphere of a season without full stands, it is understandable if Liverpool's desire has dropped off this season.

City suffered themselves last season after racking up 198 points in the previous two campaigns.

After the record-breaking numbers set by City and Liverpool over the past three years, the points tally required to win the title this season will fall.

The complexities of a coronavirus-affected campaign have been attributed to more surprise results, but an improvement in the Premier League's middle class has also played its part.

Aston Villa, Everton, Southampton and West Ham have propelled themselves into contention for Europe, while Leicester are again threatening to challenge for the title, asking more questions of the traditional top six.