The absence of defender Virgil van Dijk is having a knock-on effect at Liverpool as the Premier League champions struggle at the other end of the pitch, according to Ray Houghton.

Van Dijk was the stand-out player when the Reds clinched their first top flight title in 30 years last season but has been sidelined since injuring his knee against Everton in October.

A blunt attack, which has failed to score in their last four Premier League outings, has been primarily blamed for their drop to fourth place in the table.

Houghton, who played with the Reds from 1987 to 1992, pointed out that while Liverpool have been creating attacking chances, they are not clinical enough and that, allied to several enforced positional changes has led to their recent steep decline.

A long-term injury to defender Joe Gomez and a shorter spell out for Joel Matip have also hindered Jurgen Klopp's side. 

"If you lose Van Dijk and you lose Matip and Gomez, which is the heartbeat of the central defence, what you do then is you bring back Fabinho from central midfield to centre-back and likewise with Jordan Henderson and that might weaken the midfield slightly," Houghton told RTÉ’s Saturday Sport.

"And one of the areas where Liverpool aren’t quite doing as well is that they aren’t breaking from midfield into advanced positions.

"That’s something they were doing with the three forwards coming a little bit deeper, leaving the gaps to move into.

"Two of the full-backs, Trent Alexander-Arnold and Andy Robertson, were two of the best going forward and producing opportunities. But their final ball isn’t of the best quality at the moment, hence the reason they aren't getting those clear-cut opportunities inside the 18-yard box."

Liverpool are currently six points behind leaders Manchester United having picked up just three points from their last five games.

Former Republic of Ireland midfielder Houghton, however, believes his old side can recover and play a part in one of the most open title races in years.

"Based on what happened when I was at Liverpool, I remember going through seasons where in the first half you weren’t quite at it as much as you should have been and then you galvanize and you come together," he said.

"I’ve heard James Milner and one or two of the other Liverpool players saying it’s time the players stood up, we’ve got to put it right on the pitch, and he’s absolutely right.

"This will test the Liverpool players because the last two and a half seasons they’ve been fantastic, winning the Champions League, winning the league.

"I think there’s enough quality in this Liverpool side, once they start winning again and get that winning feeling back, they’ll go on a very good run."